bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/custom/MouseNavigator.java

   1 /**
   2  * Copyright (c) 2019 Laurent CARON.
   3  *
   4  * This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License 2.0
   6  * which accompanies this distribution, and is available at
   7  * https://www.eclipse.org/legal/epl-2.0/
   8  *
   9  * SPDX-License-Identifier: EPL-2.0
  10  *
  11  * Contributors:
  12  * Laurent CARON (laurent.caron at gmail dot com) - initial API and implementation (bug 542777)
  13  */
  14 package org.eclipse.swt.custom;
  15
  16 import org.eclipse.swt.*;
  17 import org.eclipse.swt.graphics.*;
  18 import org.eclipse.swt.widgets.*;
  19
  20 /**
  21  * This class add the following behaviour to <code>StyledText</code> widgets:
  22  * <p>
  23  * When the user clicks on the wheel, a circle with arrows appears. When the user moves the mouse,
  24  * the StyledText content is scrolled (on the right or on the left for horizontal movements, up or down for vertical movements).
  25  * </p>
  26  *
  27  * @since 3.110
  28  */
  29 class MouseNavigator {
  30         private final StyledText parent;
  31         boolean navigationActivated = false;
  32         private GC gc;
  33         private static final int CIRCLE_RADIUS = 15;
  34         private static final int CENTRAL_POINT_RADIUS = 2;
  35         private Point originalMouseLocation;
  36         private final Listener mouseDownListener, mouseUpListener, paintListener, mouseMoveListener, focusOutListener;
  37         private boolean hasHBar, hasVBar;
  38         private Cursor previousCursor;
  39
  40         MouseNavigator(final StyledText styledText) {
  41                 if (styledText == null) {
  42                         SWT.error(SWT.ERROR_NULL_ARGUMENT);
  43                 }
  44                 if (styledText.isDisposed()) {
  45                         SWT.error(SWT.ERROR_WIDGET_DISPOSED);
  46                 }
  47                 parent = styledText;
  48
  49                 mouseDownListener = (event) -> {
  50                         onMouseDown(event);
  51                 };
  52                 parent.addListener(SWT.MouseDown, mouseDownListener);
  53
  54                 mouseUpListener = (event) -> {
  55                         onMouseUp(event);
  56                 };
  57                 parent.addListener(SWT.MouseUp, mouseUpListener);
  58
  59                 paintListener = (event) -> {
  60                         onPaint(event);
  61                 };
  62                 parent.addListener(SWT.Paint, paintListener);
  63
  64                 mouseMoveListener = (event) -> {
  65                         onMouseMove(event);
  66                 };
  67                 parent.addListener(SWT.MouseMove, mouseMoveListener);
  68
  69                 focusOutListener = (event) -> {
  70                         onFocusOut(event);
  71                 };
  72                 parent.addListener(SWT.FocusOut, focusOutListener);
  73         }
  74
  75         void onMouseDown(Event e) {
  76                 if ((e.button != 2) || navigationActivated) {
  77                         return;
  78                 }
  79
  80                 if (!parent.isVisible() || !parent.getEnabled() || parent.middleClickPressed) {
  81                         return;
  82                 }
  83
  84                 // Widget has no bar or bars are not enabled
  85                 initBarState();
  86
  87                 if (!hasHBar && !hasVBar) {
  88                         return;
  89                 }
  90
  91                 navigationActivated = true;
  92                 previousCursor = parent.getCursor();
  93                 parent.setCursor(parent.getDisplay().getSystemCursor(SWT.CURSOR_ARROW));
  94                 originalMouseLocation = getMouseLocation();
  95                 parent.redraw();
  96         }
  97
  98         private void initBarState() {
  99                 hasHBar = computeHasHorizontalBar();
 100                 hasVBar = computeHasVerticalBar();
 101         }
 102
 103         private boolean computeHasHorizontalBar() {
 104                 final ScrollBar horizontalBar = parent.getHorizontalBar();
 105                 final boolean hasHorizontalBar = horizontalBar != null && horizontalBar.isVisible();
 106                 final boolean exceedHorizontalSpace = parent.computeSize(SWT.DEFAULT, SWT.DEFAULT).x > parent.getSize().x;
 107                 return hasHorizontalBar && exceedHorizontalSpace;
 108         }
 109
 110         private boolean computeHasVerticalBar() {
 111                 final ScrollBar verticalBar = parent.getVerticalBar();
 112                 final boolean hasVerticalBar = verticalBar != null && verticalBar.isEnabled();
 113                 final boolean exceedVerticalSpace = parent.computeSize(SWT.DEFAULT, SWT.DEFAULT).y > parent.getSize().y;
 114                 return hasVerticalBar && exceedVerticalSpace;
 115         }
 116
 117         private void onMouseUp(Event e) {
 118                 if ((computeDist() < CIRCLE_RADIUS) && (computeDist() >= 0)) {
 119                         return;
 120                 }
 121                 deactivate();
 122         }
 123
 124         public int computeDist() {
 125                 if (originalMouseLocation == null) {
 126                         return -1;
 127                 }
 128                 final Point mouseLocation = getMouseLocation();
 129                 final int deltaX = originalMouseLocation.x - mouseLocation.x;
 130                 final int deltaY = originalMouseLocation.y - mouseLocation.y;
 131                 final int dist = (int) Math.sqrt(deltaX * deltaX + deltaY * deltaY);
 132                 return dist;
 133         }
 134
 135         private void deactivate() {
 136                 parent.setCursor(previousCursor);
 137                 navigationActivated = false;
 138                 originalMouseLocation = null;
 139                 parent.redraw();
 140         }
 141
 142         private void onFocusOut(Event e) {
 143                 deactivate();
 144         }
 145
 146         private void onMouseMove(Event e) {
 147                 if (!navigationActivated) {
 148                         return;
 149                 }
 150
 151                 final Point mouseLocation = getMouseLocation();
 152                 final int deltaX = originalMouseLocation.x - mouseLocation.x;
 153                 final int deltaY = originalMouseLocation.y - mouseLocation.y;
 154                 final int dist = (int) Math.sqrt(deltaX * deltaX + deltaY * deltaY);
 155                 if (dist < CIRCLE_RADIUS) {
 156                         return;
 157                 }
 158
 159                 parent.setRedraw(false);
 160                 if (hasHBar) {
 161                         final ScrollBar bar = parent.getHorizontalBar();
 162                         bar.setSelection((int) (bar.getSelection() - deltaX * .1));
 163                         fireSelectionEvent(e, bar);
 164                 }
 165
 166                 if (hasVBar) {
 167                         final ScrollBar bar = parent.getVerticalBar();
 168                         bar.setSelection((int) (bar.getSelection() - deltaY * .1));
 169                         fireSelectionEvent(e, bar);
 170                 }
 171                 parent.setRedraw(true);
 172                 parent.redraw();
 173         }
 174
 175         private void fireSelectionEvent(final Event e, final ScrollBar bar) {
 176                 final Event event = new Event();
 177                 event.widget = bar;
 178                 event.display = parent.getDisplay();
 179                 event.type = SWT.Selection;
 180                 event.time = e.time;
 181
 182                 for (final Listener selectionListener : bar.getListeners(SWT.Selection)) {
 183                         selectionListener.handleEvent(event);
 184                 }
 185         }
 186
 187         private Point getMouseLocation() {
 188                 final Point cursorLocation = Display.getCurrent().getCursorLocation();
 189                 final Point relativeCursorLocation = parent.toControl(cursorLocation);
 190                 return relativeCursorLocation;
 191         }
 192
 193         private void onPaint(final Event e) {
 194                 if (!navigationActivated) {
 195                         return;
 196                 }
 197
 198                 final Rectangle rect = parent.getClientArea();
 199                 if (rect.width == 0 || rect.height == 0) {
 200                         return;
 201                 }
 202                 gc = e.gc;
 203                 gc.setAntialias(SWT.ON);
 204                 gc.setAdvanced(true);
 205
 206                 final Color oldForegroundColor = gc.getForeground();
 207                 final Color oldBackgroundColor = gc.getBackground();
 208                 gc.setBackground(parent.getForeground());
 209
 210                 drawCircle();
 211                 drawCentralPoint();
 212
 213                 drawArrows();
 214
 215                 gc.setForeground(oldForegroundColor);
 216                 gc.setBackground(oldBackgroundColor);
 217         }
 218
 219         private void drawCircle() {
 220                 gc.setBackground(parent.getBackground());
 221                 gc.setForeground(parent.getForeground());
 222                 gc.setAlpha(200);
 223                 gc.fillOval(originalMouseLocation.x - CIRCLE_RADIUS, originalMouseLocation.y - CIRCLE_RADIUS, CIRCLE_RADIUS * 2, CIRCLE_RADIUS * 2);
 224                 gc.setBackground(parent.getForeground());
 225                 gc.setAlpha(255);
 226                 gc.drawOval(originalMouseLocation.x - CIRCLE_RADIUS, originalMouseLocation.y - CIRCLE_RADIUS, CIRCLE_RADIUS * 2, CIRCLE_RADIUS * 2);
 227         }
 228
 229         private void drawCentralPoint() {
 230                 gc.fillOval(originalMouseLocation.x - CENTRAL_POINT_RADIUS, originalMouseLocation.y - CENTRAL_POINT_RADIUS, CENTRAL_POINT_RADIUS * 2, CENTRAL_POINT_RADIUS * 2);
 231         }
 232
 233         private void drawArrows() {
 234                 gc.setLineWidth(2);
 235                 if (hasHBar) {
 236                         drawHorizontalArrows();
 237                 }
 238                 if (hasVBar) {
 239                         drawVerticalArrows();
 240                 }
 241         }
 242
 243         private void drawHorizontalArrows() {
 244                 final int[] points = new int[6];
 245                 // Left
 246                 points[0] = originalMouseLocation.x - 6;
 247                 points[1] = originalMouseLocation.y + 3;
 248                 points[2] = originalMouseLocation.x - 9;
 249                 points[3] = originalMouseLocation.y;
 250                 points[4] = originalMouseLocation.x - 6;
 251                 points[5] = originalMouseLocation.y - 3;
 252                 gc.drawPolyline(points);
 253
 254                 // Right
 255                 points[0] = originalMouseLocation.x + 7;
 256                 points[1] = originalMouseLocation.y + 3;
 257                 points[2] = originalMouseLocation.x + 10;
 258                 points[3] = originalMouseLocation.y;
 259                 points[4] = originalMouseLocation.x + 7;
 260                 points[5] = originalMouseLocation.y - 3;
 261                 gc.drawPolyline(points);
 262         }
 263
 264         private void drawVerticalArrows() {
 265                 final int[] points = new int[6];
 266                 // Upper
 267                 points[0] = originalMouseLocation.x - 3;
 268                 points[1] = originalMouseLocation.y - 6;
 269                 points[2] = originalMouseLocation.x;
 270                 points[3] = originalMouseLocation.y - 10;
 271                 points[4] = originalMouseLocation.x + 3;
 272                 points[5] = originalMouseLocation.y - 6;
 273                 gc.drawPolyline(points);
 274
 275                 // Lower
 276                 points[0] = originalMouseLocation.x - 3;
 277                 points[1] = originalMouseLocation.y + 7;
 278                 points[2] = originalMouseLocation.x;
 279                 points[3] = originalMouseLocation.y + 11;
 280                 points[4] = originalMouseLocation.x + 3;
 281                 points[5] = originalMouseLocation.y + 7;
 282                 gc.drawPolyline(points);
 283
 284         }
 285
 286         void dispose() {
 287                 if (parent.isDisposed()) {
 288                         return;
 289                 }
 290                 parent.removeListener(SWT.MouseDown, mouseDownListener);
 291                 parent.removeListener(SWT.MouseUp, mouseUpListener);
 292                 parent.removeListener(SWT.Paint, paintListener);
 293                 parent.removeListener(SWT.MouseMove, mouseMoveListener);
 294                 parent.removeListener(SWT.MouseExit, focusOutListener);
 295         }
 296 }