/* FunctionEditor.cpp
 *
 * Copyright (C) 1992-2011,2012,2013,2014,2015,2017 Paul Boersma
 *
 * This code is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This code is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this work. If not, see <http://www.gnu.org/licenses/>.
 */

#include "FunctionEditor.h"
#include "machine.h"
#include "EditorM.h"
#include "GuiP.h"

Thing_implement (FunctionEditor, Editor, 0);

#define maximumScrollBarValue  2000000000
#define RELATIVE_PAGE_INCREMENT  0.8
#define SCROLL_INCREMENT_FRACTION  20
#define space 30
#define MARGIN 107
#define BOTTOM_MARGIN  2
#define TOP_MARGIN  3
#define TEXT_HEIGHT  50
#define BUTTON_X  3
#define BUTTON_WIDTH  40
#define BUTTON_SPACING  8

#include "prefs_define.h"
#include "FunctionEditor_prefs.h"
#include "prefs_install.h"
#include "FunctionEditor_prefs.h"
#include "prefs_copyToInstance.h"
#include "FunctionEditor_prefs.h"

namespace {
	constexpr int maxGroup { 100 };
	int nGroup = 0;
	FunctionEditor theGroup [1 + maxGroup];
}

static void drawWhileDragging (FunctionEditor me, double x1, double x2);

static int group_equalDomain (double tmin, double tmax) {
	if (nGroup == 0) return 1;
	for (int i = 1; i <= maxGroup; i ++)
		if (theGroup [i])
			return tmin == theGroup [i] -> tmin && tmax == theGroup [i] -> tmax;
	return 0;   // should not occur
}

static void updateScrollBar (FunctionEditor me) {
/* We cannot call this immediately after creation. */
	double slider_size = (my endWindow - my startWindow) / (my tmax - my tmin) * maximumScrollBarValue - 1.0;
	double value = (my startWindow - my tmin) / (my tmax - my tmin) * maximumScrollBarValue + 1.0;
	if (slider_size < 1.0) slider_size = 1.0;
	if (value > maximumScrollBarValue - slider_size)
		value = maximumScrollBarValue - slider_size;
	if (value < 1.0) value = 1.0;
	double increment = slider_size / SCROLL_INCREMENT_FRACTION + 1.0;
	double page_increment = RELATIVE_PAGE_INCREMENT * slider_size + 1.0;
	GuiScrollBar_set (my scrollBar, undefined, maximumScrollBarValue, value, slider_size, increment, page_increment);
}

static void updateGroup (FunctionEditor me) {
	if (! my group) return;
	for (int i = 1; i <= maxGroup; i ++) if (theGroup [i] && theGroup [i] != me) {
		FunctionEditor thee = theGroup [i];
		if (my pref_synchronizedZoomAndScroll ()) {
			thy startWindow = my startWindow;
			thy endWindow = my endWindow;
		}
		thy startSelection = my startSelection;
		thy endSelection = my endSelection;
		FunctionEditor_updateText (thee);
		updateScrollBar (thee);
		Graphics_updateWs (thy graphics.get());
	}
}

static void drawNow (FunctionEditor me) {
	bool leftFromWindow = my startWindow > my tmin;
	bool rightFromWindow = my endWindow < my tmax;
	bool cursorVisible = my startSelection == my endSelection && my startSelection >= my startWindow && my startSelection <= my endWindow;
	bool selection = my endSelection > my startSelection;

	/* Update selection. */

	bool beginVisible = my startSelection > my startWindow && my startSelection < my endWindow;
	bool endVisible = my endSelection > my startWindow && my endSelection < my endWindow;

	/* Update markers. */

	my numberOfMarkers = 0;
	if (beginVisible)
		my marker [++ my numberOfMarkers] = my startSelection;
	if (endVisible && my endSelection != my startSelection)
		my marker [++ my numberOfMarkers] = my endSelection;
	my marker [++ my numberOfMarkers] = my endWindow;
	VECsort_inplace (VEC (my marker, my numberOfMarkers));

	/* Update rectangles. */

	for (int i = 0; i < 8; i++)
		my rect [i]. left = my rect [i]. right = 0;

	/* 0: rectangle for total. */

	my rect [0]. left = my functionViewerLeft + ( leftFromWindow ? 0 : MARGIN );
	my rect [0]. right = my functionViewerRight - ( rightFromWindow ? 0 : MARGIN );
	my rect [0]. bottom = BOTTOM_MARGIN;
	my rect [0]. top = BOTTOM_MARGIN + space;

	/* 1: rectangle for visible part. */

	my rect [1]. left = my functionViewerLeft + MARGIN;
	my rect [1]. right = my functionViewerRight - MARGIN;
	my rect [1]. bottom = BOTTOM_MARGIN + space;
	my rect [1]. top = BOTTOM_MARGIN + space * (my numberOfMarkers > 1 ? 2 : 3);

	/* 2: rectangle for left from visible part. */

	if (leftFromWindow) {
		my rect [2]. left = my functionViewerLeft;
		my rect [2]. right = my functionViewerLeft + MARGIN;
		my rect [2]. bottom = BOTTOM_MARGIN + space;
		my rect [2]. top = BOTTOM_MARGIN + space * 2;
	}

	/* 3: rectangle for right from visible part. */

	if (rightFromWindow) {
		my rect [3]. left = my functionViewerRight - MARGIN;
		my rect [3]. right = my functionViewerRight;
		my rect [3]. bottom = BOTTOM_MARGIN + space;
		my rect [3]. top = BOTTOM_MARGIN + space * 2;
	}

	/* 4, 5, 6: rectangles between markers visible in visible part. */

	if (my numberOfMarkers > 1) {
		double window = my endWindow - my startWindow;
		for (int i = 1; i <= my numberOfMarkers; i ++) {
			my rect [3 + i]. left = i == 1 ? my functionViewerLeft + MARGIN : my functionViewerLeft + MARGIN + (my functionViewerRight - my functionViewerLeft - MARGIN * 2) *
				(my marker [i - 1] - my startWindow) / window;
			my rect [3 + i]. right = my functionViewerLeft + MARGIN + (my functionViewerRight - my functionViewerLeft - MARGIN * 2) *
				(my marker [i] - my startWindow) / window;
			my rect [3 + i]. bottom = BOTTOM_MARGIN + space * 2;
			my rect [3 + i]. top = BOTTOM_MARGIN + space * 3;
		}
	}
	
	if (selection) {
		double window = my endWindow - my startWindow;
		double left =
			my startSelection == my startWindow ? my functionViewerLeft + MARGIN :
			my startSelection == my tmin ? my functionViewerLeft :
			my startSelection < my startWindow ? my functionViewerLeft + MARGIN * 0.3 :
			my startSelection < my endWindow ? my functionViewerLeft + MARGIN + (my functionViewerRight - my functionViewerLeft - MARGIN * 2) * (my startSelection - my startWindow) / window :
			my startSelection == my endWindow ? my functionViewerRight - MARGIN : my functionViewerRight - MARGIN * 0.7;
		double right =
			my endSelection < my startWindow ? my functionViewerLeft + MARGIN * 0.7 :
			my endSelection == my startWindow ? my functionViewerLeft + MARGIN :
			my endSelection < my endWindow ? my functionViewerLeft + MARGIN + (my functionViewerRight - my functionViewerLeft - MARGIN * 2) * (my endSelection - my startWindow) / window :
			my endSelection == my endWindow ? my functionViewerRight - MARGIN :
			my endSelection < my tmax ? my functionViewerRight - MARGIN * 0.3 : my functionViewerRight;
		my rect [7]. left = left;
		my rect [7]. right = right;
		my rect [7]. bottom = my height - space - TOP_MARGIN;
		my rect [7]. top = my height - TOP_MARGIN;
	}

	/*
	 * Be responsive: update the markers now.
	 */
	Graphics_setViewport (my graphics.get(), my functionViewerLeft, my functionViewerRight, 0.0, my height);
	Graphics_setWindow (my graphics.get(), my functionViewerLeft, my functionViewerRight, 0.0, my height);
	Graphics_setColour (my graphics.get(), Graphics_WINDOW_BACKGROUND_COLOUR);
	Graphics_fillRectangle (my graphics.get(), my functionViewerLeft + MARGIN, my selectionViewerRight - MARGIN, my height - (TOP_MARGIN + space), my height);
	Graphics_fillRectangle (my graphics.get(), my functionViewerLeft, my functionViewerLeft + MARGIN, BOTTOM_MARGIN + ( leftFromWindow ? space * 2 : 0 ), my height);
	Graphics_fillRectangle (my graphics.get(), my functionViewerRight - MARGIN, my functionViewerRight, BOTTOM_MARGIN + ( rightFromWindow ? space * 2 : 0 ), my height);
	if (my p_showSelectionViewer) {
		Graphics_setViewport (my graphics.get(), my selectionViewerLeft, my selectionViewerRight, 0.0, my height);
		Graphics_setWindow (my graphics.get(), my selectionViewerLeft, my selectionViewerRight, 0.0, my height);
		Graphics_fillRectangle (my graphics.get(), my selectionViewerLeft, my selectionViewerLeft + MARGIN, BOTTOM_MARGIN, my height);
		Graphics_fillRectangle (my graphics.get(), my selectionViewerRight - MARGIN, my selectionViewerRight, BOTTOM_MARGIN, my height);
		Graphics_fillRectangle (my graphics.get(), my selectionViewerLeft + MARGIN, my selectionViewerRight - MARGIN, 0, BOTTOM_MARGIN + space * 3);
	}
	Graphics_setGrey (my graphics.get(), 0.0);
	#if defined (macintosh)
		Graphics_line (my graphics.get(), my functionViewerLeft, 2.0, my selectionViewerRight, 2.0);
		Graphics_line (my graphics.get(), my functionViewerLeft, my height - 2.0, my selectionViewerRight, my height - 2.0);
	#endif

	Graphics_setViewport (my graphics.get(), my functionViewerLeft, my functionViewerRight, 0.0, my height);
	Graphics_setWindow (my graphics.get(), my functionViewerLeft, my functionViewerRight, 0.0, my height);
	Graphics_setTextAlignment (my graphics.get(), Graphics_CENTRE, Graphics_HALF);
	for (int i = 0; i < 8; i ++) {
		double left = my rect [i]. left, right = my rect [i]. right;
		if (left < right)
			Graphics_button (my graphics.get(), left, right, my rect [i]. bottom, my rect [i]. top);
	}
	double verticalCorrection = my height / (my height - 111.0 + 11.0);
	#ifdef _WIN32
		verticalCorrection *= 1.5;
	#endif
	for (int i = 0; i < 8; i ++) {
		double left = my rect [i]. left, right = my rect [i]. right;
		double bottom = my rect [i]. bottom, top = my rect [i]. top;
		if (left < right) {
			const char *format = my v_format_long ();
			double value = undefined, inverseValue = 0.0;
			switch (i) {
				case 0: {
					format = my v_format_totalDuration ();
					value = my tmax - my tmin;
				} break; case 1: {
					format = my v_format_window ();
					value = my endWindow - my startWindow;
					/*
						Window domain text.
					*/	
					Graphics_setColour (my graphics.get(), Graphics_BLUE);
					Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, Graphics_HALF);
					Graphics_text (my graphics.get(), left, 0.5 * (bottom + top) - verticalCorrection,
						Melder_fixed (my startWindow, my v_fixedPrecision_long ()));
					Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_HALF);
					Graphics_text (my graphics.get(), right, 0.5 * (bottom + top) - verticalCorrection,
						Melder_fixed (my endWindow, my v_fixedPrecision_long ()));
					Graphics_setColour (my graphics.get(), Graphics_BLACK);
					Graphics_setTextAlignment (my graphics.get(), Graphics_CENTRE, Graphics_HALF);
				} break; case 2: {
					value = my startWindow - my tmin;
				} break; case 3: {
					value = my tmax - my endWindow;
				} break; case 4: {
					value = my marker [1] - my startWindow;
				} break; case 5: {
					value = my marker [2] - my marker [1];
				} break; case 6: {
					value = my marker [3] - my marker [2];
				} break; case 7: {
					format = my v_format_selection ();
					value = my endSelection - my startSelection;
					inverseValue = 1.0 / value;
				}
			}
			char text8 [100];
			snprintf (text8, 100, format, value, inverseValue);
			autostring32 text = Melder_8to32 (text8);
			if (Graphics_textWidth (my graphics.get(), text.get()) < right - left) {
				Graphics_text (my graphics.get(), 0.5 * (left + right), 0.5 * (bottom + top) - verticalCorrection, text.get());
			} else if (format == my v_format_long ()) {
				snprintf (text8, 100, my v_format_short (), value);
				text = Melder_8to32 (text8);
				if (Graphics_textWidth (my graphics.get(), text.get()) < right - left)
					Graphics_text (my graphics.get(), 0.5 * (left + right), 0.5 * (bottom + top) - verticalCorrection, text.get());
			} else {
				snprintf (text8, 100, my v_format_long (), value);
				text = Melder_8to32 (text8);
				if (Graphics_textWidth (my graphics.get(), text.get()) < right - left) {
						Graphics_text (my graphics.get(), 0.5 * (left + right), 0.5 * (bottom + top) - verticalCorrection, text.get());
				} else {
					snprintf (text8, 100, my v_format_short (), my endSelection - my startSelection);
					text = Melder_8to32 (text8);
					if (Graphics_textWidth (my graphics.get(), text.get()) < right - left)
						Graphics_text (my graphics.get(), 0.5 * (left + right), 0.5 * (bottom + top) - verticalCorrection, text.get());
				}
			}
		}
	}

	Graphics_setViewport (my graphics.get(), my functionViewerLeft + MARGIN, my functionViewerRight - MARGIN, 0.0, my height);
	Graphics_setWindow (my graphics.get(), my startWindow, my endWindow, 0.0, my height);
	/*Graphics_setColour (my graphics.get(), Graphics_WHITE);
	Graphics_fillRectangle (my graphics.get(), my startWindow, my endWindow, BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));*/
	Graphics_setColour (my graphics.get(), Graphics_BLACK);
	Graphics_rectangle (my graphics.get(), my startWindow, my endWindow, BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));

	/*
	 * Red marker text.
	 */
	Graphics_setColour (my graphics.get(), Graphics_RED);
	if (cursorVisible) {
		Graphics_setTextAlignment (my graphics.get(), Graphics_CENTRE, Graphics_BOTTOM);
		Graphics_text (my graphics.get(), my startSelection, my height - (TOP_MARGIN + space) - verticalCorrection,
			Melder_fixed (my startSelection, my v_fixedPrecision_long ()));
	}
	if (beginVisible && selection) {
		Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_HALF);
		Graphics_text (my graphics.get(), my startSelection, my height - (TOP_MARGIN + space/2) - verticalCorrection,
			Melder_fixed (my startSelection, my v_fixedPrecision_long ()));
	}
	if (endVisible && selection) {
		Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, Graphics_HALF);
		Graphics_text (my graphics.get(), my endSelection, my height - (TOP_MARGIN + space/2) - verticalCorrection,
			Melder_fixed (my endSelection, my v_fixedPrecision_long ()));
	}
	Graphics_setColour (my graphics.get(), Graphics_BLACK);

	/*
	 * To reduce flashing, give our descendants the opportunity to prepare their data.
	 */
	my v_prepareDraw ();

	/*
	 * Start of inner drawing.
	 */
	Graphics_setViewport (my graphics.get(), my functionViewerLeft + MARGIN, my functionViewerRight - MARGIN, BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));

	my v_draw ();
	Graphics_setViewport (my graphics.get(), my functionViewerLeft + MARGIN, my functionViewerRight - MARGIN, BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));

	/*
	 * Red dotted marker lines.
	 */
	Graphics_setWindow (my graphics.get(), my startWindow, my endWindow, 0.0, 1.0);
	Graphics_setColour (my graphics.get(), Graphics_RED);
	Graphics_setLineType (my graphics.get(), Graphics_DOTTED);
	double bottom = my v_getBottomOfSoundAndAnalysisArea ();
	if (cursorVisible)
		Graphics_line (my graphics.get(), my startSelection, bottom, my startSelection, 1.0);
	if (beginVisible)
		Graphics_line (my graphics.get(), my startSelection, bottom, my startSelection, 1.0);
	if (endVisible)
		Graphics_line (my graphics.get(), my endSelection, bottom, my endSelection, 1.0);
	Graphics_setColour (my graphics.get(), Graphics_BLACK);
	Graphics_setLineType (my graphics.get(), Graphics_DRAWN);

	/*
	 * Highlight selection.
	 */
	if (selection && my startSelection < my endWindow && my endSelection > my startWindow) {
		double left = my startSelection, right = my endSelection;
		if (left < my startWindow) left = my startWindow;
		if (right > my endWindow) right = my endWindow;
		my v_highlightSelection (left, right, 0.0, 1.0);
	}

	/*
	 * Draw the selection part.
	 */
	if (my p_showSelectionViewer) {
		Graphics_setViewport (my graphics.get(), my selectionViewerLeft + MARGIN, my selectionViewerRight - MARGIN, BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));
		my v_drawSelectionViewer ();
	}

	/*
	 * End of inner drawing.
	 */
	Graphics_flushWs (my graphics.get());
	Graphics_setViewport (my graphics.get(), my functionViewerLeft, my selectionViewerRight, 0.0, my height);
}

/********** METHODS **********/

void structFunctionEditor :: v_destroy () noexcept {
	MelderAudio_stopPlaying (MelderAudio_IMPLICIT);
	if (our group) {   // undangle
		int i = 1;
		while (theGroup [i] != this) {
			Melder_assert (i < maxGroup);
			i ++;
		}
		theGroup [i] = nullptr;
		nGroup --;
	}
	FunctionEditor_Parent :: v_destroy ();
}

void structFunctionEditor :: v_info () {
	FunctionEditor_Parent :: v_info ();
	MelderInfo_writeLine (U"Editor start: ", our tmin, U" ", v_format_units ());
	MelderInfo_writeLine (U"Editor end: ", our tmax, U" ", v_format_units ());
	MelderInfo_writeLine (U"Window start: ", our startWindow, U" ", v_format_units ());
	MelderInfo_writeLine (U"Window end: ", our endWindow, U" ", v_format_units ());
	MelderInfo_writeLine (U"Selection start: ", our startSelection, U" ", v_format_units ());
	MelderInfo_writeLine (U"Selection end: ", our endSelection, U" ", v_format_units ());
	MelderInfo_writeLine (U"Arrow scroll step: ", our p_arrowScrollStep, U" ", v_format_units ());
	MelderInfo_writeLine (U"Group: ", group ? U"yes" : U"no");
}

/********** FILE MENU **********/

static void gui_drawingarea_cb_resize (FunctionEditor me, GuiDrawingArea_ResizeEvent event) {
	if (! my graphics) return;   // could be the case in the very beginning
	Graphics_setWsViewport (my graphics.get(), 0, event -> width, 0, event -> height);
	int width = event -> width + 21;
	/*
	 * Put the function viewer at the left and the selection viewer at the right.
	 */
	my functionViewerLeft = 0;
	my functionViewerRight = my p_showSelectionViewer ? Melder_ifloor (width * (2.0/3.0)) : width;
	my selectionViewerLeft = my functionViewerRight;
	my selectionViewerRight = width;
	my height = event -> height + 111;
	Graphics_setWsWindow (my graphics.get(), 0.0, width, 0.0, my height);
	Graphics_setViewport (my graphics.get(), 0.0, width, 0.0, my height);
	Graphics_updateWs (my graphics.get());

	/* Save the current shell size as the user's preference for a new FunctionEditor. */

	my pref_shellWidth  () = GuiShell_getShellWidth  (my windowForm);
	my pref_shellHeight () = GuiShell_getShellHeight (my windowForm);
}

static void menu_cb_preferences (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Preferences", nullptr)
		BOOLEAN (synchronizeZoomAndScroll, U"Synchronize zoom and scroll", my default_synchronizedZoomAndScroll ())
		BOOLEAN (showSelectionViewer, U"Show selection viewer", my default_showSelectionViewer ())
		POSITIVE (arrowScrollStep, Melder_cat (U"Arrow scroll step (", my v_format_units (), U")"), my default_arrowScrollStep ())
		my v_prefs_addFields (cmd);
	EDITOR_OK
		SET_BOOLEAN (synchronizeZoomAndScroll, my pref_synchronizedZoomAndScroll ())
		SET_BOOLEAN (showSelectionViewer, my pref_showSelectionViewer())
		SET_REAL (arrowScrollStep, my p_arrowScrollStep)
		my v_prefs_setValues (cmd);
	EDITOR_DO
		bool oldSynchronizedZoomAndScroll = my pref_synchronizedZoomAndScroll ();
		bool oldShowSelectionViewer = my p_showSelectionViewer;
		my pref_synchronizedZoomAndScroll () = synchronizeZoomAndScroll;
		my pref_showSelectionViewer () = my p_showSelectionViewer = showSelectionViewer;
		my pref_arrowScrollStep () = my p_arrowScrollStep = arrowScrollStep;
		if (my p_showSelectionViewer != oldShowSelectionViewer) {
			struct structGuiDrawingArea_ResizeEvent event { my drawingArea, 0, 0 };
			event. width  = GuiControl_getWidth  (my drawingArea);
			event. height = GuiControl_getHeight (my drawingArea);
			gui_drawingarea_cb_resize (me, & event);
		}
		if (! oldSynchronizedZoomAndScroll && my pref_synchronizedZoomAndScroll ()) {
			updateGroup (me);
		}
		my v_prefs_getValues (cmd);
	EDITOR_END
}

static bool v_form_pictureSelection_drawSelectionTimes;
static bool v_form_pictureSelection_drawSelectionHairs;
void structFunctionEditor :: v_form_pictureSelection (EditorCommand cmd) {
	UiForm_addBoolean (cmd -> d_uiform.get(), & v_form_pictureSelection_drawSelectionTimes, nullptr, U"Draw selection times", true);
	UiForm_addBoolean (cmd -> d_uiform.get(), & v_form_pictureSelection_drawSelectionHairs, nullptr, U"Draw selection hairs", true);
}
void structFunctionEditor :: v_ok_pictureSelection (EditorCommand cmd) {
	FunctionEditor me = (FunctionEditor) cmd -> d_editor;
	SET_BOOLEAN (v_form_pictureSelection_drawSelectionTimes, my pref_picture_drawSelectionTimes ())
	SET_BOOLEAN (v_form_pictureSelection_drawSelectionHairs, my pref_picture_drawSelectionHairs ())
}
void structFunctionEditor :: v_do_pictureSelection (EditorCommand cmd) {
	FunctionEditor me = (FunctionEditor) cmd -> d_editor;
	my pref_picture_drawSelectionTimes () = v_form_pictureSelection_drawSelectionTimes;
	my pref_picture_drawSelectionHairs () = v_form_pictureSelection_drawSelectionHairs;
}

/********** QUERY MENU **********/

static void menu_cb_getB (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	Melder_informationReal (my startSelection, my v_format_units ());
}
static void menu_cb_getCursor (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	Melder_informationReal (0.5 * (my startSelection + my endSelection), my v_format_units ());
}
static void menu_cb_getE (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	Melder_informationReal (my endSelection, my v_format_units ());
}
static void menu_cb_getSelectionDuration (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	Melder_informationReal (my endSelection - my startSelection, my v_format_units ());
}

/********** VIEW MENU **********/

static void menu_cb_zoom (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Zoom", nullptr)
		REAL (from, U"From", U"0.0")
		REAL (to,   U"To",   U"1.0")
	EDITOR_OK
		SET_REAL (from, my startWindow)
		SET_REAL (to,   my endWindow)
	EDITOR_DO
		my startWindow = from;
		if (my startWindow < my tmin + 1e-12)
			my startWindow = my tmin;
		my endWindow = to;
		if (my endWindow > my tmax - 1e-12)
			my endWindow = my tmax;
		my v_updateText ();
		updateScrollBar (me);
		/*Graphics_updateWs (my graphics);*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

static void do_showAll (FunctionEditor me) {
	my startWindow = my tmin;
	my endWindow = my tmax;
	my v_updateText ();
	updateScrollBar (me);
	/*Graphics_updateWs (my graphics);*/ drawNow (me);
	if (my pref_synchronizedZoomAndScroll ()) {
		updateGroup (me);
	}
}

static void gui_button_cb_showAll (FunctionEditor me, GuiButtonEvent /* event */) {
	do_showAll (me);
}

static void do_zoomIn (FunctionEditor me) {
	double shift = (my endWindow - my startWindow) / 4;
	my startWindow += shift;
	my endWindow -= shift;
	my v_updateText ();
	updateScrollBar (me);
	/*Graphics_updateWs (my graphics);*/ drawNow (me);
	if (my pref_synchronizedZoomAndScroll ()) {
		updateGroup (me);
	}
}

static void gui_button_cb_zoomIn (FunctionEditor me, GuiButtonEvent /* event */) {
	do_zoomIn (me);
}

static void do_zoomOut (FunctionEditor me) {
	double shift = (my endWindow - my startWindow) / 2;
	MelderAudio_stopPlaying (MelderAudio_IMPLICIT);   // quickly, before window changes
	my startWindow -= shift;
	if (my startWindow < my tmin + 1e-12)
		my startWindow = my tmin;
	my endWindow += shift;
	if (my endWindow > my tmax - 1e-12)
		my endWindow = my tmax;
	my v_updateText ();
	updateScrollBar (me);
	/*Graphics_updateWs (my graphics);*/ drawNow (me);
	if (my pref_synchronizedZoomAndScroll ()) {
		updateGroup (me);
	}
}

static void gui_button_cb_zoomOut (FunctionEditor me, GuiButtonEvent /*event*/) {
	do_zoomOut (me);
}

static void do_zoomToSelection (FunctionEditor me) {
	if (my endSelection > my startSelection) {
		my startZoomHistory = my startWindow;   // remember for Zoom Back
		my endZoomHistory = my endWindow;   // remember for Zoom Back
		trace (U"Zooming in to ", my startSelection, U" ~ ", my endSelection, U" seconds.");
		my startWindow = my startSelection;
		my endWindow = my endSelection;
		trace (U"Zoomed in to ", my startWindow, U" ~ ", my endWindow, U" seconds (1).");
		my v_updateText ();
		trace (U"Zoomed in to ", my startWindow, U" ~ ", my endWindow, U" seconds (2).");
		updateScrollBar (me);
		trace (U"Zoomed in to ", my startWindow, U" ~ ", my endWindow, U" seconds (3).");
		/*Graphics_updateWs (my graphics);*/ drawNow (me);
		if (my pref_synchronizedZoomAndScroll ()) {
			updateGroup (me);
		}
		trace (U"Zoomed in to ", my startWindow, U" ~ ", my endWindow, U" seconds (4).");
	}
}

static void gui_button_cb_zoomToSelection (FunctionEditor me, GuiButtonEvent /* event */) {
	do_zoomToSelection (me);
}

static void do_zoomBack (FunctionEditor me) {
	if (my endZoomHistory > my startZoomHistory) {
		my startWindow = my startZoomHistory;
		my endWindow = my endZoomHistory;
		my v_updateText ();
		updateScrollBar (me);
		/*Graphics_updateWs (my graphics);*/ drawNow (me);
		if (my pref_synchronizedZoomAndScroll ()) {
			updateGroup (me);
		}
	}
}

static void gui_button_cb_zoomBack (FunctionEditor me, GuiButtonEvent /* event */) {
	do_zoomBack (me);
}

static void menu_cb_showAll (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	do_showAll (me);
}

static void menu_cb_zoomIn (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	do_zoomIn (me);
}

static void menu_cb_zoomOut (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	do_zoomOut (me);
}

static void menu_cb_zoomToSelection (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	do_zoomToSelection (me);
}

static void menu_cb_zoomBack (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	do_zoomBack (me);
}

static void menu_cb_play (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Play", nullptr)
		REAL (from, U"From", U"0.0")
		REAL (to,   U"To",   U"1.0")
	EDITOR_OK
		SET_REAL (from, my startWindow)
		SET_REAL (to,   my endWindow)
	EDITOR_DO
		MelderAudio_stopPlaying (MelderAudio_IMPLICIT);
		my v_play (from, to);
	EDITOR_END
}

static void menu_cb_playOrStop (FunctionEditor me, EDITOR_ARGS_FORM) {
	if (MelderAudio_isPlaying) {
		MelderAudio_stopPlaying (MelderAudio_EXPLICIT);
	} else if (my startSelection < my endSelection) {
		my playingSelection = true;
		my v_play (my startSelection, my endSelection);
	} else {
		my playingCursor = true;
		if (my startSelection == my endSelection && my startSelection > my startWindow && my startSelection < my endWindow)
			my v_play (my startSelection, my endWindow);
		else
			my v_play (my startWindow, my endWindow);
	}
}

static void menu_cb_playWindow (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	MelderAudio_stopPlaying (MelderAudio_IMPLICIT);
	my playingCursor = true;
	my v_play (my startWindow, my endWindow);
}

static void menu_cb_interruptPlaying (FunctionEditor /* me */, EDITOR_ARGS_DIRECT) {
	MelderAudio_stopPlaying (MelderAudio_IMPLICIT);
}

/********** SELECT MENU **********/

static void menu_cb_select (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Select", nullptr)
		REAL (startOfSelection, U"Start of selection", U"0.0")
		REAL (endOfSelection,   U"End of selection", U"1.0")
	EDITOR_OK
		SET_REAL (startOfSelection, my startSelection)
		SET_REAL (endOfSelection,   my endSelection)
	EDITOR_DO
		my startSelection = startOfSelection;
		if (my startSelection < my tmin + 1e-12)
			my startSelection = my tmin;
		my endSelection = endOfSelection;
		if (my endSelection > my tmax - 1e-12)
			my endSelection = my tmax;
		if (my startSelection > my endSelection) {
			double dummy = my startSelection;
			my startSelection = my endSelection;
			my endSelection = dummy;
		}
		my v_updateText ();
		/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

static void menu_cb_moveCursorToB (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my endSelection = my startSelection;
	my v_updateText ();
	/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
	updateGroup (me);
}

static void menu_cb_moveCursorToE (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my startSelection = my endSelection;
	my v_updateText ();
	/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
	updateGroup (me);
}

static void menu_cb_moveCursorTo (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Move cursor to", nullptr)
		REAL (position, U"Position", U"0.0")
	EDITOR_OK
		SET_REAL (position, 0.5 * (my startSelection + my endSelection))
	EDITOR_DO
		if (position < my tmin + 1e-12) position = my tmin;
		if (position > my tmax - 1e-12) position = my tmax;
		my startSelection = my endSelection = position;
		my v_updateText ();
		/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

static void menu_cb_moveCursorBy (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Move cursor by", nullptr)
		REAL (distance, U"Distance", U"0.05")
	EDITOR_OK
	EDITOR_DO
		double position = 0.5 * (my startSelection + my endSelection) + distance;
		if (position < my tmin) position = my tmin;
		if (position > my tmax) position = my tmax;
		my startSelection = my endSelection = position;
		my v_updateText ();
		/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

static void menu_cb_moveBby (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Move start of selection by", nullptr)
		REAL (distance, U"Distance", U"0.05")
	EDITOR_OK
	EDITOR_DO
		double position = my startSelection + distance;
		if (position < my tmin) position = my tmin;
		if (position > my tmax) position = my tmax;
		my startSelection = position;
		if (my startSelection > my endSelection) {
			double dummy = my startSelection;
			my startSelection = my endSelection;
			my endSelection = dummy;
		}
		my v_updateText ();
		/*Graphics_updateWs (my graphics,get());*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

static void menu_cb_moveEby (FunctionEditor me, EDITOR_ARGS_FORM) {
	EDITOR_FORM (U"Move end of selection by", nullptr)
		REAL (distance, U"Distance", U"0.05")
	EDITOR_OK
	EDITOR_DO
		double position = my endSelection + distance;
		if (position < my tmin) position = my tmin;
		if (position > my tmax) position = my tmax;
		my endSelection = position;
		if (my startSelection > my endSelection) {
			double dummy = my startSelection;
			my startSelection = my endSelection;
			my endSelection = dummy;
		}
		my v_updateText ();
		/*Graphics_updateWs (my graphics.get());*/ drawNow (me);
		updateGroup (me);
	EDITOR_END
}

void FunctionEditor_shift (FunctionEditor me, double shift, bool needsUpdateGroup) {
	double windowLength = my endWindow - my startWindow;
	MelderAudio_stopPlaying (MelderAudio_IMPLICIT);   // quickly, before window changes
	trace (U"shifting by ", shift);
	if (shift < 0.0) {
		my startWindow += shift;
		if (my startWindow < my tmin + 1e-12)
			my startWindow = my tmin;
		my endWindow = my startWindow + windowLength;
		if (my endWindow > my tmax - 1e-12)
			my endWindow = my tmax;
	} else {
		my endWindow += shift;
		if (my endWindow > my tmax - 1e-12)
			my endWindow = my tmax;
		my startWindow = my endWindow - windowLength;
		if (my startWindow < my tmin + 1e-12)
			my startWindow = my tmin;
	}
	FunctionEditor_marksChanged (me, needsUpdateGroup);
}

static void menu_cb_pageUp (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	FunctionEditor_shift (me, -RELATIVE_PAGE_INCREMENT * (my endWindow - my startWindow), true);
}

static void menu_cb_pageDown (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	FunctionEditor_shift (me, +RELATIVE_PAGE_INCREMENT * (my endWindow - my startWindow), true);
}

static void scrollToView (FunctionEditor me, double t) {
	if (t <= my startWindow) {
		FunctionEditor_shift (me, t - my startWindow - 0.618 * (my endWindow - my startWindow), true);
	} else if (t >= my endWindow) {
		FunctionEditor_shift (me, t - my endWindow + 0.618 * (my endWindow - my startWindow), true);
	} else {
		FunctionEditor_marksChanged (me, true);
	}
}

static void menu_cb_selectEarlier (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my startSelection -= my p_arrowScrollStep;
	if (my startSelection < my tmin + 1e-12)
		my startSelection = my tmin;
	my endSelection -= my p_arrowScrollStep;
	if (my endSelection < my tmin + 1e-12)
		my endSelection = my tmin;
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

static void menu_cb_selectLater (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my startSelection += my p_arrowScrollStep;
	if (my startSelection > my tmax - 1e-12)
		my startSelection = my tmax;
	my endSelection += my p_arrowScrollStep;
	if (my endSelection > my tmax - 1e-12)
		my endSelection = my tmax;
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

static void menu_cb_moveBleft (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my startSelection -= my p_arrowScrollStep;
	if (my startSelection < my tmin + 1e-12)
		my startSelection = my tmin;
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

static void menu_cb_moveBright (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my startSelection += my p_arrowScrollStep;
	if (my startSelection > my tmax - 1e-12)
		my startSelection = my tmax;
	if (my startSelection > my endSelection) {
		double dummy = my startSelection;
		my startSelection = my endSelection;
		my endSelection = dummy;
	}
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

static void menu_cb_moveEleft (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my endSelection -= my p_arrowScrollStep;
	if (my endSelection < my tmin + 1e-12)
		my endSelection = my tmin;
	if (my startSelection > my endSelection) {
		double dummy = my startSelection;
		my startSelection = my endSelection;
		my endSelection = dummy;
	}
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

static void menu_cb_moveEright (FunctionEditor me, EDITOR_ARGS_DIRECT) {
	my endSelection += my p_arrowScrollStep;
	if (my endSelection > my tmax - 1e-12)
		my endSelection = my tmax;
	scrollToView (me, 0.5 * (my startSelection + my endSelection));
}

/********** GUI CALLBACKS **********/

static void gui_cb_scroll (FunctionEditor me, GuiScrollBarEvent event) {
	if (! my graphics) return;   // ignore events during creation
	double value = GuiScrollBar_getValue (event -> scrollBar);
	double shift = my tmin + (value - 1) * (my tmax - my tmin) / maximumScrollBarValue - my startWindow;
	bool shifted = shift != 0.0;
	double oldSliderSize = (my endWindow - my startWindow) / (my tmax - my tmin) * maximumScrollBarValue - 1.0;
	double newSliderSize = GuiScrollBar_getSliderSize (event -> scrollBar);
	bool zoomed = newSliderSize != oldSliderSize;
	#if ! cocoa
		zoomed = false;
	#endif
	if (shifted) {
		my startWindow += shift;
		if (my startWindow < my tmin + 1e-12) my startWindow = my tmin;
		my endWindow += shift;
		if (my endWindow > my tmax - 1e-12) my endWindow = my tmax;
	}
	if (zoomed) {
		double zoom = (newSliderSize + 1) * (my tmax - my tmin) / maximumScrollBarValue;
		my endWindow = my startWindow + zoom;
		if (my endWindow > my tmax - 1e-12) my endWindow = my tmax;
	}
	if (shifted || zoomed) {
		my v_updateText ();
		updateScrollBar (me);
		#if cocoa
			Graphics_updateWs (my graphics.get());
		#else
			/*Graphics_clearWs (my graphics.get());*/
			drawNow (me);   // do not wait for expose event
		#endif
		if (! my group || ! my pref_synchronizedZoomAndScroll ()) return;
		for (int i = 1; i <= maxGroup; i ++) if (theGroup [i] && theGroup [i] != me) {
			theGroup [i] -> startWindow = my startWindow;
			theGroup [i] -> endWindow = my endWindow;
			FunctionEditor_updateText (theGroup [i]);
			updateScrollBar (theGroup [i]);
			#if cocoa
				Graphics_updateWs (theGroup [i] -> graphics.get());
			#else
				Graphics_clearWs (theGroup [i] -> graphics.get());
				drawNow (theGroup [i]);
			#endif
		}
	}
}

static void gui_checkbutton_cb_group (FunctionEditor me, GuiCheckButtonEvent /* event */) {
	int i;
	my group = ! my group;
	if (my group) {
		FunctionEditor thee;
		i = 1; while (theGroup [i]) i ++; theGroup [i] = me;
		if (++ nGroup == 1) { Graphics_updateWs (my graphics.get()); return; }
		i = 1; while (! theGroup [i] || theGroup [i] == me) i ++; thee = theGroup [i];
		if (my pref_synchronizedZoomAndScroll ()) {
			my startWindow = thy startWindow;
			my endWindow = thy endWindow;
		}
		my startSelection = thy startSelection;
		my endSelection = thy endSelection;
		if (my tmin > thy tmin || my tmax < thy tmax) {
			if (my tmin > thy tmin) my tmin = thy tmin;
			if (my tmax < thy tmax) my tmax = thy tmax;
			my v_updateText ();
			updateScrollBar (me);
			Graphics_updateWs (my graphics.get());
		} else {
			my v_updateText ();
			updateScrollBar (me);
			Graphics_updateWs (my graphics.get());
			if (my tmin < thy tmin || my tmax > thy tmax)
				for (i = 1; i <= maxGroup; i ++) if (theGroup [i] && theGroup [i] != me) {
					if (my tmin < thy tmin)
						theGroup [i] -> tmin = my tmin;
					if (my tmax > thy tmax)
						theGroup [i] -> tmax = my tmax;
					FunctionEditor_updateText (theGroup [i]);
					updateScrollBar (theGroup [i]);
					Graphics_updateWs (theGroup [i] -> graphics.get());
				}
		}
	} else {
		i = 1; while (theGroup [i] != me) i ++; theGroup [i] = nullptr;
		nGroup --;
		my v_updateText ();
		Graphics_updateWs (my graphics.get());   // for setting buttons in draw method
	}
	if (my group) updateGroup (me);
}

static void menu_cb_intro (FunctionEditor /* me */, EDITOR_ARGS_DIRECT) {
	Melder_help (U"Intro");
}

void structFunctionEditor :: v_createMenuItems_file (EditorMenu menu) {
	FunctionEditor_Parent :: v_createMenuItems_file (menu);
	EditorMenu_addCommand (menu, U"Preferences...", 0, menu_cb_preferences);
	EditorMenu_addCommand (menu, U"-- after preferences --", 0, nullptr);
}

void structFunctionEditor :: v_createMenuItems_view_timeDomain (EditorMenu menu) {
	EditorMenu_addCommand (menu, v_format_domain (), GuiMenu_INSENSITIVE, menu_cb_zoom /* dummy */);
	EditorMenu_addCommand (menu, U"Zoom...", 0, menu_cb_zoom);
	EditorMenu_addCommand (menu, U"Show all", 'A', menu_cb_showAll);
	EditorMenu_addCommand (menu, U"Zoom in", 'I', menu_cb_zoomIn);
	EditorMenu_addCommand (menu, U"Zoom out", 'O', menu_cb_zoomOut);
	EditorMenu_addCommand (menu, U"Zoom to selection", 'N', menu_cb_zoomToSelection);
	EditorMenu_addCommand (menu, U"Zoom back", 'B', menu_cb_zoomBack);
	EditorMenu_addCommand (menu, U"Scroll page back", GuiMenu_PAGE_UP, menu_cb_pageUp);
	EditorMenu_addCommand (menu, U"Scroll page forward", GuiMenu_PAGE_DOWN, menu_cb_pageDown);
}

void structFunctionEditor :: v_createMenuItems_view_audio (EditorMenu menu) {
	EditorMenu_addCommand (menu, U"-- play --", 0, nullptr);
	EditorMenu_addCommand (menu, U"Audio:", GuiMenu_INSENSITIVE, menu_cb_play /* dummy */);
	EditorMenu_addCommand (menu, U"Play...", 0, menu_cb_play);
	EditorMenu_addCommand (menu, U"Play or stop", GuiMenu_TAB, menu_cb_playOrStop);
	EditorMenu_addCommand (menu, U"Play window", GuiMenu_SHIFT | GuiMenu_TAB, menu_cb_playWindow);
	EditorMenu_addCommand (menu, U"Interrupt playing", GuiMenu_ESCAPE, menu_cb_interruptPlaying);
}

void structFunctionEditor :: v_createMenuItems_view (EditorMenu menu) {
	v_createMenuItems_view_timeDomain (menu);
	v_createMenuItems_view_audio (menu);
}

void structFunctionEditor :: v_createMenuItems_query (EditorMenu menu) {
	FunctionEditor_Parent :: v_createMenuItems_query (menu);
	EditorMenu_addCommand (menu, U"-- query selection --", 0, nullptr);
	EditorMenu_addCommand (menu, U"Get start of selection", 0, menu_cb_getB);
	EditorMenu_addCommand (menu, U"Get begin of selection", Editor_HIDDEN, menu_cb_getB);
	EditorMenu_addCommand (menu, U"Get cursor", GuiMenu_F6, menu_cb_getCursor);
	EditorMenu_addCommand (menu, U"Get end of selection", 0, menu_cb_getE);
	EditorMenu_addCommand (menu, U"Get selection length", 0, menu_cb_getSelectionDuration);
}

void structFunctionEditor :: v_createMenus () {
	FunctionEditor_Parent :: v_createMenus ();
	EditorMenu menu;

	menu = Editor_addMenu (this, U"View", 0);
	v_createMenuItems_view (menu);

	Editor_addMenu (this, U"Select", 0);
	Editor_addCommand (this, U"Select", U"Select...", 0, menu_cb_select);
	Editor_addCommand (this, U"Select", U"Move cursor to start of selection", 0, menu_cb_moveCursorToB);
	Editor_addCommand (this, U"Select", U"Move cursor to begin of selection", Editor_HIDDEN, menu_cb_moveCursorToB);
	Editor_addCommand (this, U"Select", U"Move cursor to end of selection", 0, menu_cb_moveCursorToE);
	Editor_addCommand (this, U"Select", U"Move cursor to...", 0, menu_cb_moveCursorTo);
	Editor_addCommand (this, U"Select", U"Move cursor by...", 0, menu_cb_moveCursorBy);
	Editor_addCommand (this, U"Select", U"Move start of selection by...", 0, menu_cb_moveBby);
	Editor_addCommand (this, U"Select", U"Move begin of selection by...", Editor_HIDDEN, menu_cb_moveBby);
	Editor_addCommand (this, U"Select", U"Move end of selection by...", 0, menu_cb_moveEby);
	/*Editor_addCommand (this, U"Select", U"Move cursor back by half a second", motif_, menu_cb_moveCursorBy);*/
	Editor_addCommand (this, U"Select", U"Select earlier", GuiMenu_UP_ARROW, menu_cb_selectEarlier);
	Editor_addCommand (this, U"Select", U"Select later", GuiMenu_DOWN_ARROW, menu_cb_selectLater);
	Editor_addCommand (this, U"Select", U"Move start of selection left", GuiMenu_SHIFT | GuiMenu_UP_ARROW, menu_cb_moveBleft);
	Editor_addCommand (this, U"Select", U"Move begin of selection left", Editor_HIDDEN, menu_cb_moveBleft);
	Editor_addCommand (this, U"Select", U"Move start of selection right", GuiMenu_SHIFT | GuiMenu_DOWN_ARROW, menu_cb_moveBright);
	Editor_addCommand (this, U"Select", U"Move begin of selection right", Editor_HIDDEN, menu_cb_moveBright);
	Editor_addCommand (this, U"Select", U"Move end of selection left", GuiMenu_COMMAND | GuiMenu_UP_ARROW, menu_cb_moveEleft);
	Editor_addCommand (this, U"Select", U"Move end of selection right", GuiMenu_COMMAND | GuiMenu_DOWN_ARROW, menu_cb_moveEright);
}

void structFunctionEditor :: v_createHelpMenuItems (EditorMenu menu) {
	FunctionEditor_Parent :: v_createHelpMenuItems (menu);
	EditorMenu_addCommand (menu, U"Intro", 0, menu_cb_intro);
}

static void gui_drawingarea_cb_expose (FunctionEditor me, GuiDrawingArea_ExposeEvent /* event */) {
	if (! my graphics) return;   // could be the case in the very beginning
	if (my enableUpdates)
		drawNow (me);
}

static void gui_drawingarea_cb_click (FunctionEditor me, GuiDrawingArea_ClickEvent event) {
	if (! my graphics) return;   // could be the case in the very beginning
	my shiftKeyPressed = event -> shiftKeyPressed;
	Graphics_setWindow (my graphics.get(), my functionViewerLeft, my selectionViewerRight, 0.0, my height);
	double xWC, yWC;
	Graphics_DCtoWC (my graphics.get(), event -> x, event -> y, & xWC, & yWC);

	if (xWC > my selectionViewerLeft)
	{
		Graphics_setViewport (my graphics.get(), my selectionViewerLeft + MARGIN, my selectionViewerRight - MARGIN,
			BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));
		Graphics_setWindow (my graphics.get(), 0.0, 1.0, 0.0, 1.0);
		Graphics_DCtoWC (my graphics.get(), event -> x, event -> y, & xWC, & yWC);
		my v_clickSelectionViewer (xWC, yWC);
		//my v_updateText ();
		drawNow (me);
		updateGroup (me);
	}
	else if (yWC > BOTTOM_MARGIN + space * 3 && yWC < my height - (TOP_MARGIN + space)) {   // in signal region?
		bool needsUpdate;
		Graphics_setViewport (my graphics.get(), my functionViewerLeft + MARGIN, my functionViewerRight - MARGIN,
			BOTTOM_MARGIN + space * 3, my height - (TOP_MARGIN + space));
		Graphics_setWindow (my graphics.get(), my startWindow, my endWindow, 0.0, 1.0);
		Graphics_DCtoWC (my graphics.get(), event -> x, event -> y, & xWC, & yWC);
		if (xWC < my startWindow) xWC = my startWindow;
		if (xWC > my endWindow) xWC = my endWindow;
		if (Melder_debug == 24) {
			Melder_casual (U"FunctionEditor::gui_drawingarea_cb_click:"
				U" button ", event -> button,
				U" shift ", my shiftKeyPressed,
				U" option ", event -> optionKeyPressed,
				U" command ", event -> commandKeyPressed,
				U" control ", event -> extraControlKeyPressed);
		}
#if defined (macintosh)
		needsUpdate =
			event -> optionKeyPressed || event -> extraControlKeyPressed ? my v_clickB (xWC, yWC) :
			event -> commandKeyPressed ? my v_clickE (xWC, yWC) :
			my v_click (xWC, yWC, my shiftKeyPressed);
#elif defined (_WIN32)
		needsUpdate =
			event -> commandKeyPressed ? my v_clickB (xWC, yWC) :
			event -> optionKeyPressed ? my v_clickE (xWC, yWC) :
			my v_click (xWC, yWC, my shiftKeyPressed);
#else
		needsUpdate =
			event -> commandKeyPressed ? my v_clickB (xWC, yWC) :
			event -> optionKeyPressed ? my v_clickE (xWC, yWC) :
			event -> button == 1 ? my v_click (xWC, yWC, my shiftKeyPressed) :
			event -> button == 2 ? my v_clickB (xWC, yWC) : my v_clickE (xWC, yWC);
#endif
		if (needsUpdate) my v_updateText ();
		Graphics_setViewport (my graphics.get(), my functionViewerLeft, my functionViewerRight, 0, my height);
		if (needsUpdate) {
			drawNow (me);
		}
		if (needsUpdate) updateGroup (me);
	}
	else   // clicked outside signal region? Let us hear it
	{
		try {
			for (int i = 0; i < 8; i ++) {
				if (xWC > my rect [i]. left && xWC < my rect [i]. right &&
					 yWC > my rect [i]. bottom && yWC < my rect [i]. top)
					switch (i) {
						case 0: my v_play (my tmin, my tmax); break;
						case 1: my v_play (my startWindow, my endWindow); break;
						case 2: my v_play (my tmin, my startWindow); break;
						case 3: my v_play (my endWindow, my tmax); break;
						case 4: my v_play (my startWindow, my marker [1]); break;
						case 5: my v_play (my marker [1], my marker [2]); break;
						case 6: my v_play (my marker [2], my marker [3]); break;
						case 7: my v_play (my startSelection, my endSelection); break;
					}
			}
		} catch (MelderError) {
			Melder_flushError ();
		}
	}
}

void structFunctionEditor :: v_createChildren () {
	int x = BUTTON_X;

	/***** Create zoom buttons. *****/

	GuiButton_createShown (our windowForm, x, x + BUTTON_WIDTH, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"all", gui_button_cb_showAll, this, 0);
	x += BUTTON_WIDTH + BUTTON_SPACING;
	GuiButton_createShown (our windowForm, x, x + BUTTON_WIDTH, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"in", gui_button_cb_zoomIn, this, 0);
	x += BUTTON_WIDTH + BUTTON_SPACING;
	GuiButton_createShown (our windowForm, x, x + BUTTON_WIDTH, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"out", gui_button_cb_zoomOut, this, 0);
	x += BUTTON_WIDTH + BUTTON_SPACING;
	GuiButton_createShown (our windowForm, x, x + BUTTON_WIDTH, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"sel", gui_button_cb_zoomToSelection, this, 0);
	x += BUTTON_WIDTH + BUTTON_SPACING;
	GuiButton_createShown (our windowForm, x, x + BUTTON_WIDTH, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"bak", gui_button_cb_zoomBack, this, 0);

	/***** Create scroll bar. *****/

	our scrollBar = GuiScrollBar_createShown (our windowForm,
		x += BUTTON_WIDTH + BUTTON_SPACING, -80 - BUTTON_SPACING, -4 - Gui_PUSHBUTTON_HEIGHT, 0,
		1, maximumScrollBarValue, 1, maximumScrollBarValue - 1, 1, 1,
		gui_cb_scroll, this, GuiScrollBar_HORIZONTAL);

	/***** Create Group button. *****/

	our groupButton = GuiCheckButton_createShown (our windowForm, -80, 0, -4 - Gui_PUSHBUTTON_HEIGHT, -4,
		U"Group", gui_checkbutton_cb_group, this, group_equalDomain (our tmin, our tmax) ? GuiCheckButton_SET : 0);

	/***** Create optional text field. *****/

	if (our v_hasText ()) {
		our text = GuiText_createShown (our windowForm, 0, 0,
			Machine_getMenuBarHeight (),
			Machine_getMenuBarHeight () + TEXT_HEIGHT, GuiText_WORDWRAP | GuiText_MULTILINE);
		#if gtk
			Melder_assert (our text -> d_widget);
			gtk_widget_grab_focus (GTK_WIDGET (our text -> d_widget));   // BUG: can hardly be correct (the text should grab the focus of the window, not the global focus)
		#elif cocoa
			Melder_assert ([(NSView *) our text -> d_widget window]);
			//[[(NSView *) our text -> d_widget window] setInitialFirstResponder: (NSView *) our text -> d_widget];
			[[(NSView *) our text -> d_widget window] makeFirstResponder: (NSView *) our text -> d_widget];
		#endif
	}

	/***** Create drawing area. *****/

	#if cocoa
		int marginBetweenTextAndDrawingAreaToEnsureCorrectUnhighlighting = 3;
	#else
		int marginBetweenTextAndDrawingAreaToEnsureCorrectUnhighlighting = 0;
	#endif
	our drawingArea = GuiDrawingArea_createShown (our windowForm,
		0, 0,
		Machine_getMenuBarHeight () + ( our v_hasText () ? TEXT_HEIGHT + marginBetweenTextAndDrawingAreaToEnsureCorrectUnhighlighting : 0), -8 - Gui_PUSHBUTTON_HEIGHT,
		gui_drawingarea_cb_expose, gui_drawingarea_cb_click, nullptr, gui_drawingarea_cb_resize, this, 0);
	GuiDrawingArea_setSwipable (our drawingArea, our scrollBar, nullptr);
}

void structFunctionEditor :: v_dataChanged () {
	Function function = (Function) our data;
	Melder_assert (Thing_isa (function, classFunction));
	our tmin = function -> xmin;
 	our tmax = function -> xmax;
 	if (our startWindow < our tmin || our startWindow > our tmax) our startWindow = our tmin;
 	if (our endWindow < our tmin || our endWindow > our tmax) our endWindow = our tmax;
 	if (our startWindow >= our endWindow) { our startWindow = our tmin; our endWindow = our tmax; }
 	if (our startSelection < our tmin) our startSelection = our tmin;
 	if (our startSelection > our tmax) our startSelection = our tmax;
 	if (our endSelection < our tmin) our endSelection = our tmin;
 	if (our endSelection > our tmax) our endSelection = our tmax;
	FunctionEditor_marksChanged (this, false);
}

static void drawWhileDragging (FunctionEditor me, double x1, double x2) {
	/*
	 * We must draw this within the window, because the window tends to have a white background.
	 * We cannot draw this in the margins, because these tend to be grey, so that Graphics_xorOn does not work properly.
	 * We draw the text twice, because we expect that not ALL of the window is white...
	 */
	double xleft, xright;
	if (x1 > x2) xleft = x2, xright = x1; else xleft = x1, xright = x2;
	Graphics_xorOn (my graphics.get(), Graphics_MAROON);
	Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_TOP);
	Graphics_text (my graphics.get(), xleft, 1.0, Melder_fixed (xleft, 6));
	Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, Graphics_TOP);
	Graphics_text (my graphics.get(), xright, 1.0, Melder_fixed (xright, 6));
	Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_BOTTOM);
	Graphics_text (my graphics.get(), xleft, 0.0, Melder_fixed (xleft, 6));
	Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, Graphics_BOTTOM);
	Graphics_text (my graphics.get(), xright, 0.0, Melder_fixed (xright, 6));
	Graphics_setLineType (my graphics.get(), Graphics_DOTTED);
	Graphics_line (my graphics.get(), xleft, 0.0, xleft, 1.0);
	Graphics_line (my graphics.get(), xright, 0.0, xright, 1.0);
	Graphics_setLineType (my graphics.get(), Graphics_DRAWN);
	Graphics_xorOff (my graphics.get());
}

bool structFunctionEditor :: v_click (double xbegin, double ybegin, bool a_shiftKeyPressed) {
	bool drag = false;
	double x = xbegin, y = ybegin;

	/*
	 * The 'anchor' is the point that will stay fixed during dragging.
	 * For instance, if she clicks and drags to the right,
	 * the location at which she originally clicked will be the anchor,
	 * even if she later chooses to drag the mouse to the left of it.
	 * Another example: if she shift-clicks near E, B will become (and stay) the anchor.
	 */

	Graphics_setWindow (our graphics.get(), our startWindow, our endWindow, 0.0, 1.0);

	double anchorForDragging = xbegin;   // the default (for if the shift key isn't pressed)
	if (a_shiftKeyPressed) {
		/*
		 * Extend the selection.
		 * We should always end up with a real selection (B < E),
		 * even if we start with the reversed temporal order (E < B).
		 */
		bool reversed = our startSelection > our endSelection;
		double firstMark = reversed ? our endSelection : our startSelection;
		double secondMark = reversed ? our startSelection : our endSelection;
		/*
		 * Undraw the old selection.
		 */
		if (our endSelection > our startSelection) {
			/*
			 * Determine the visible part of the old selection.
			 */
			double startVisible = our startSelection > our startWindow ? our startSelection : our startWindow;
			double endVisible = our endSelection < our endWindow ? our endSelection : our endWindow;
			/*
			 * Undraw the visible part of the old selection.
			 */
			if (endVisible > startVisible) {
				v_unhighlightSelection (startVisible, endVisible, 0, 1);
				//Graphics_flushWs (our graphics.get());
			}
		}
		if (xbegin >= secondMark) {
		 	/*
			 * She clicked right from the second mark (usually E). We move E.
			 */
			our endSelection = xbegin;
			anchorForDragging = our startSelection;
		} else if (xbegin <= firstMark) {
		 	/*
			 * She clicked left from the first mark (usually B). We move B.
			 */
			our startSelection = xbegin;
			anchorForDragging = our endSelection;
		} else {
			/*
			 * She clicked in between the two marks. We move the nearest mark.
			 */
			double distanceOfClickToFirstMark = fabs (xbegin - firstMark);
			double distanceOfClickToSecondMark = fabs (xbegin - secondMark);
			/*
			 * We make sure that the marks are in the unmarked B - E order.
			 */
			if (reversed) {
				/*
				 * Swap B and E.
				 */
				our startSelection = firstMark;
				our endSelection = secondMark;
			}
			/*
			 * Move the nearest mark.
			 */
			if (distanceOfClickToFirstMark < distanceOfClickToSecondMark) {
				our startSelection = xbegin;
				anchorForDragging = our endSelection;
			} else {
				our endSelection = xbegin;
				anchorForDragging = our startSelection;
			}
		}
		/*
		 * Draw the new selection.
		 */
		if (our endSelection > our startSelection) {
			/*
			 * Determine the visible part of the new selection.
			 */
			double startVisible = our startSelection > our startWindow ? our startSelection : our startWindow;
			double endVisible = our endSelection < our endWindow ? our endSelection : our endWindow;
			/*
			 * Draw the visible part of the new selection.
			 */
			if (endVisible > startVisible)
				v_highlightSelection (startVisible, endVisible, 0.0, 1.0);
		}
	}
	/*
	 * Find out whether this is a click or a drag.
	 */
    
	while (Graphics_mouseStillDown (our graphics.get())) {
		Graphics_getMouseLocation (our graphics.get(), & x, & y);
		if (x < our startWindow) x = our startWindow;
		if (x > our endWindow) x = our endWindow;
		if (fabs (Graphics_dxWCtoMM (our graphics.get(), x - xbegin)) > 1.5) {
			drag = true;
			break;
		}
	}
    
	if (drag) {
		/*
		 * First undraw the old selection.
		 */
		if (our endSelection > our startSelection) {
			/*
			 * Determine the visible part of the old selection.
			 */
			double startVisible = our startSelection > our startWindow ? our startSelection : our startWindow;
			double endVisible = our endSelection < our endWindow ? our endSelection : our endWindow;
			/*
			 * Undraw the visible part of the old selection.
			 */
			if (endVisible > startVisible)
				v_unhighlightSelection (startVisible, endVisible, 0.0, 1.0);
		}
		/*
		 * Draw the text at least once.
		 */
		/*if (x < our startWindow) x = our startWindow; else if (x > our endWindow) x = our endWindow;*/
        drawWhileDragging (this, anchorForDragging, x);
		/*
		 * Draw the dragged selection at least once.
		 */
		{
			double x1, x2;
			if (x > anchorForDragging) x1 = anchorForDragging, x2 = x; else x1 = x, x2 = anchorForDragging;
			v_highlightSelection (x1, x2, 0.0, 1.0);
		}
		/*
		 * Drag for the new selection.
		 */
        
		while (Graphics_mouseStillDown (our graphics.get()))
		{
			double xold = x, x1, x2;
			Graphics_getMouseLocation (our graphics.get(), & x, & y);
			/*
			 * Clip to the visible window. Ideally, we should perform autoscrolling instead, though...
			 */
			if (x < our startWindow) x = our startWindow; else if (x > our endWindow) x = our endWindow;
            
			if (x == xold)
				continue;
            
			/*
			 * Undraw previous dragged selection.
			 */
			if (xold > anchorForDragging) x1 = anchorForDragging, x2 = xold; else x1 = xold, x2 = anchorForDragging;
			if (x1 != x2) v_unhighlightSelection (x1, x2, 0.0, 1.0);
			/*
			 * Undraw the text.
			 */
			drawWhileDragging (this, anchorForDragging, xold);
			/*
			 * Redraw the text at the new location.
			 */
            drawWhileDragging (this, anchorForDragging, x);
			/*
			 * Draw new dragged selection.
			 */
			if (x > anchorForDragging) x1 = anchorForDragging, x2 = x; else x1 = x, x2 = anchorForDragging;
			if (x1 != x2) v_highlightSelection (x1, x2, 0.0, 1.0);
        } ;
		/*
		 * Set the new selection.
		 */
		if (x > anchorForDragging) our startSelection = anchorForDragging, our endSelection = x;
		else our startSelection = x, our endSelection = anchorForDragging;
	} else if (! a_shiftKeyPressed) {
		/*
		 * Move the cursor to the clicked position.
		 */
		our startSelection = our endSelection = xbegin;
	}
	return FunctionEditor_UPDATE_NEEDED;
}

bool structFunctionEditor :: v_clickB (double xWC, double /* yWC */) {
	our startSelection = xWC;
	if (our startSelection > our endSelection) {
		double dummy = our startSelection;
		our startSelection = our endSelection;
		our endSelection = dummy;
	}
	return FunctionEditor_UPDATE_NEEDED;
}

bool structFunctionEditor :: v_clickE (double xWC, double /* yWC */) {
	our endSelection = xWC;
	if (our startSelection > our endSelection) {
		double dummy = our startSelection;
		our startSelection = our endSelection;
		our endSelection = dummy;
	}
	return FunctionEditor_UPDATE_NEEDED;
}

void structFunctionEditor :: v_clickSelectionViewer (double /* xWC */, double /* yWC */) {
}

int structFunctionEditor :: v_playCallback (int phase, double /* a_tmin */, double a_tmax, double t) {
	/*
	 * This callback will often be called by the Melder workproc during playback.
	 * However, it will sometimes be called by Melder_stopPlaying with phase=3.
	 * This will occur at unpredictable times, perhaps when the LongSound is updated.
	 * So we had better make no assumptions about the current viewport.
	 */
	double x1NDC, x2NDC, y1NDC, y2NDC;
	Graphics_inqViewport (our graphics.get(), & x1NDC, & x2NDC, & y1NDC, & y2NDC);
	Graphics_setViewport (our graphics.get(),
		our functionViewerLeft + MARGIN, our functionViewerRight - MARGIN,
		BOTTOM_MARGIN + space * 3, our height - (TOP_MARGIN + space));
	Graphics_setWindow (our graphics.get(), our startWindow, our endWindow, 0.0, 1.0);
	Graphics_xorOn (our graphics.get(), Graphics_MAROON);
	/*
	 * Undraw the play cursor at its old location.
	 * BUG: during scrolling, zooming, and exposure, an ugly line may remain.
	 */
	if (phase != 1 && playCursor >= our startWindow && playCursor <= our endWindow) {
		Graphics_setLineWidth (our graphics.get(), 3.0);
		Graphics_line (our graphics.get(), playCursor, 0.0, playCursor, 1.0);
		Graphics_setLineWidth (our graphics.get(), 1.0);
	}
	/*
	 * Draw the play cursor at its new location.
	 */
	if (phase != 3 && t >= our startWindow && t <= our endWindow) {
		Graphics_setLineWidth (our graphics.get(), 3.0);
		Graphics_line (our graphics.get(), t, 0.0, t, 1.0);
		Graphics_setLineWidth (our graphics.get(), 1.0);
	}
	Graphics_xorOff (our graphics.get());
	if (our p_showSelectionViewer) {
		Graphics_setViewport (our graphics.get(),
			our selectionViewerLeft + MARGIN, our selectionViewerRight - MARGIN,
			BOTTOM_MARGIN + space * 3, our height - (TOP_MARGIN + space));
		our v_drawRealTimeSelectionViewer (phase, t);
	}
	/*
	 * Usually, there will be an event test after each invocation of this callback,
	 * because the asynchronicity is kMelder_asynchronicityLevel_INTERRUPTABLE or kMelder_asynchronicityLevel_ASYNCHRONOUS.
	 * However, if the asynchronicity is just kMelder_asynchronicityLevel_CALLING_BACK,
	 * there is no event test. Which means: no server round trip.
	 * Which means: no automatic flushing of graphics output.
	 * So: we force the flushing ourselves, lest we see too few moving cursors.
	 *
	 * At the moment, Cocoa seems to require this flushing even if the asynchronicity is kMelder_asynchronicityLevel_ASYNCHRONOUS.
	 */
	Graphics_flushWs (our graphics.get());
	Graphics_setViewport (our graphics.get(), x1NDC, x2NDC, y1NDC, y2NDC);
	playCursor = t;
	if (phase == 3) {
		if (t < a_tmax && MelderAudio_stopWasExplicit ()) {
			if (t > our startSelection && t < our endSelection)
				our startSelection = t;
			else
				our startSelection = our endSelection = t;
			v_updateText ();
			/*Graphics_updateWs (our graphics);*/ drawNow (this);
			updateGroup (this);
		}
		playingCursor = false;
		playingSelection = false;
	}
	return 1;
}

int theFunctionEditor_playCallback (FunctionEditor me, int phase, double a_tmin, double a_tmax, double t) {
	return my v_playCallback (phase, a_tmin, a_tmax, t);
}

void structFunctionEditor :: v_highlightSelection (double left, double right, double bottom, double top) {
	Graphics_highlight (our graphics.get(), left, right, bottom, top);
}

void structFunctionEditor :: v_unhighlightSelection (double left, double right, double bottom, double top) {
	Graphics_unhighlight (our graphics.get(), left, right, bottom, top);
}

void FunctionEditor_init (FunctionEditor me, conststring32 title, Function data) {
	my tmin = data -> xmin;   // set before adding children (see group button)
	my tmax = data -> xmax;
	Editor_init (me, 0, 0, my pref_shellWidth (), my pref_shellHeight (), title, data);

	my startWindow = my tmin;
	my endWindow = my tmax;
	my startSelection = my endSelection = 0.5 * (my tmin + my tmax);
	#if motif
		Melder_assert (XtWindow (my drawingArea -> d_widget));
	#endif
	my graphics = Graphics_create_xmdrawingarea (my drawingArea);
	Graphics_setFontSize (my graphics.get(), 12);

// This exdents because it's a hack:
struct structGuiDrawingArea_ResizeEvent event { my drawingArea, 0, 0 };
event. width  = GuiControl_getWidth  (my drawingArea);
event. height = GuiControl_getHeight (my drawingArea);
gui_drawingarea_cb_resize (me, & event);

	my v_updateText ();
	if (group_equalDomain (my tmin, my tmax))
		gui_checkbutton_cb_group (me, nullptr);   // BUG: nullptr
	my enableUpdates = true;
}

void FunctionEditor_marksChanged (FunctionEditor me, bool needsUpdateGroup) {
	my v_updateText ();
	updateScrollBar (me);
	/*Graphics_updateWs (my graphics);*/ drawNow (me);
	if (needsUpdateGroup)
		updateGroup (me);
}

void FunctionEditor_updateText (FunctionEditor me) {
	my v_updateText ();
}

void FunctionEditor_redraw (FunctionEditor me) {
	//Graphics_updateWs (my graphics);
	drawNow (me);
}

void FunctionEditor_enableUpdates (FunctionEditor me, bool enable) {
	my enableUpdates = enable;
}

void FunctionEditor_ungroup (FunctionEditor me) {
	if (! my group) return;
	my group = false;
	GuiCheckButton_setValue (my groupButton, false);
	int i = 1;
	while (theGroup [i] != me) i ++;
	theGroup [i] = nullptr;
	nGroup --;
	my v_updateText ();
	Graphics_updateWs (my graphics.get());   // for setting buttons in v_draw() method
}

void FunctionEditor_drawRangeMark (FunctionEditor me, double yWC, conststring32 yWC_string, conststring32 units, int verticalAlignment) {
	static MelderString text { };
	MelderString_copy (& text, yWC_string, units);
	double textWidth = Graphics_textWidth (my graphics.get(), text.string) + Graphics_dxMMtoWC (my graphics.get(), 0.5);
	Graphics_setColour (my graphics.get(), Graphics_BLUE);
	Graphics_line (my graphics.get(), my endWindow, yWC, my endWindow + textWidth, yWC);
	Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, verticalAlignment);
	if (verticalAlignment == Graphics_BOTTOM)
		yWC -= Graphics_dyMMtoWC (my graphics.get(), 0.5);
	Graphics_text (my graphics.get(), my endWindow, yWC, text.string);
}

void FunctionEditor_drawCursorFunctionValue (FunctionEditor me, double yWC, conststring32 yWC_string, conststring32 units) {
	Graphics_setColour (my graphics.get(), Graphics_CYAN);
	Graphics_line (my graphics.get(), my startWindow, yWC, 0.99 * my startWindow + 0.01 * my endWindow, yWC);
	Graphics_fillCircle_mm (my graphics.get(), 0.5 * (my startSelection + my endSelection), yWC, 1.5);
	Graphics_setColour (my graphics.get(), Graphics_BLUE);
	Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_HALF);
	Graphics_text (my graphics.get(), my startWindow, yWC,   yWC_string, units);
}

void FunctionEditor_insertCursorFunctionValue (FunctionEditor me, double yWC, conststring32 yWC_string, conststring32 units, double minimum, double maximum) {
	double textX = my endWindow, textY = yWC;
	int tooHigh = Graphics_dyWCtoMM (my graphics.get(), maximum - textY) < 5.0;
	int tooLow = Graphics_dyWCtoMM (my graphics.get(), textY - minimum) < 5.0;
	if (yWC < minimum || yWC > maximum) return;
	Graphics_setColour (my graphics.get(), Graphics_CYAN);
	Graphics_line (my graphics.get(), 0.99 * my endWindow + 0.01 * my startWindow, yWC, my endWindow, yWC);
	Graphics_fillCircle_mm (my graphics.get(), 0.5 * (my startSelection + my endSelection), yWC, 1.5);
	if (tooHigh) {
		if (tooLow) textY = 0.5 * (minimum + maximum);
		else textY = maximum - Graphics_dyMMtoWC (my graphics.get(), 5.0);
	} else if (tooLow) {
		textY = minimum + Graphics_dyMMtoWC (my graphics.get(), 5.0);
	}
	static MelderString text { };
	MelderString_copy (& text, yWC_string, units);
	double textWidth = Graphics_textWidth (my graphics.get(), text.string);
	Graphics_fillCircle_mm (my graphics.get(), my endWindow + textWidth + Graphics_dxMMtoWC (my graphics.get(), 1.5), textY, 1.5);
	Graphics_setColour (my graphics.get(), Graphics_RED);
	Graphics_setTextAlignment (my graphics.get(), Graphics_LEFT, Graphics_HALF);
	Graphics_text (my graphics.get(), textX, textY, text.string);
}

void FunctionEditor_drawHorizontalHair (FunctionEditor me, double yWC, conststring32 yWC_string, conststring32 units) {
	Graphics_setColour (my graphics.get(), Graphics_RED);
	Graphics_line (my graphics.get(), my startWindow, yWC, my endWindow, yWC);
	Graphics_setTextAlignment (my graphics.get(), Graphics_RIGHT, Graphics_HALF);
	Graphics_text (my graphics.get(), my startWindow, yWC,   yWC_string, units);
}

void FunctionEditor_drawGridLine (FunctionEditor me, double yWC) {
	Graphics_setColour (my graphics.get(), Graphics_CYAN);
	Graphics_setLineType (my graphics.get(), Graphics_DOTTED);
	Graphics_line (my graphics.get(), my startWindow, yWC, my endWindow, yWC);
	Graphics_setLineType (my graphics.get(), Graphics_DRAWN);
}

void FunctionEditor_garnish (FunctionEditor me) {
	if (my pref_picture_drawSelectionTimes ()) {
		if (my startSelection >= my startWindow && my startSelection <= my endWindow)
			Graphics_markTop (my pictureGraphics, my startSelection, true, true, false, nullptr);
		if (my endSelection != my startSelection && my endSelection >= my startWindow && my endSelection <= my endWindow)
			Graphics_markTop (my pictureGraphics, my endSelection, true, true, false, nullptr);
	}
	if (my pref_picture_drawSelectionHairs ()) {
		if (my startSelection >= my startWindow && my startSelection <= my endWindow)
			Graphics_markTop (my pictureGraphics, my startSelection, false, false, true, nullptr);
		if (my endSelection != my startSelection && my endSelection >= my startWindow && my endSelection <= my endWindow)
			Graphics_markTop (my pictureGraphics, my endSelection, false, false, true, nullptr);
	}
}

/* End of file FunctionEditor.cpp */
