Make overlay scrolling configurable via the palette settings

This adds a new checkbox to the settings dialog that allows the user to
replace the overlay scrollbar with the native scrollbar. Linux only, as
the overlay is not available on any other platforms.

Resolves eclipse#569

org.eclipse.gef/.settings/.api_filters

@@ -126,6 +126,14 @@
  </message_arguments>
  </filter>
  </resource>
+ <resource path="src/org/eclipse/gef/ui/palette/DefaultPaletteViewerPreferences.java" type="org.eclipse.gef.ui.palette.DefaultPaletteViewerPreferences">
+ <filter id="576725006">
+ <message_arguments>
+ <message_argument value="PaletteViewerPreferences"/>
+ <message_argument value="DefaultPaletteViewerPreferences"/>
+ </message_arguments>
+ </filter>
+ </resource>
  <resource path="src/org/eclipse/gef/ui/palette/PinDrawerAction.java" type="org.eclipse.gef.ui.palette.PinDrawerAction">
  <filter id="643850349">
  <message_arguments>

org.eclipse.gef/src/org/eclipse/gef/ui/palette/DefaultPaletteViewerPreferences.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2010 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -15,6 +15,7 @@
 import java.beans.PropertyChangeListener;
 import java.beans.PropertyChangeSupport;
 
+import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.FontData;
 
 import org.eclipse.jface.preference.IPreferenceStore;
@@ -76,6 +77,7 @@ public DefaultPaletteViewerPreferences(final IPreferenceStore store) {
  store.setDefault(PREFERENCE_LAYOUT, LAYOUT_LIST);
  store.setDefault(PREFERENCE_AUTO_COLLAPSE, COLLAPSE_AS_NEEDED);
  store.setDefault(PREFERENCE_FONT, DEFAULT_FONT);
+ store.setDefault(PREFERENCE_SCROLLBARS_MODE, SWT.SCROLLBAR_OVERLAY);
 
  listener = new PreferenceStoreListener();
  store.addPropertyChangeListener(listener);
@@ -231,6 +233,8 @@ protected void handlePreferenceStorePropertyChanged(String property) {
  firePropertyChanged(property, Integer.valueOf(getAutoCollapseSetting()));
  } else if (property.equals(PREFERENCE_FONT)) {
  firePropertyChanged(property, getFontData());
+ } else if (property.equals(PREFERENCE_SCROLLBARS_MODE)) {
+ firePropertyChanged(property, getScrollbarsMode());
  } else {
  firePropertyChanged(property, Boolean.valueOf(useLargeIcons(convertPreferenceNameToLayout(property))));
  }
@@ -356,4 +360,18 @@ public void propertyChange(PropertyChangeEvent evt) {
  }
  }
 
+ @Override
+ public void setScrollbarsMode(int mode) {
+ if (mode != SWT.SCROLLBAR_OVERLAY && mode != SWT.NONE) {
+ throw new IllegalArgumentException(
+ "Scrollbar mode must be either SWT.SCROLLBAR_OVERLAY or SWT.NONE, but %d was given!" //$NON-NLS-1$
+ .formatted(mode));
+ }
+ getPreferenceStore().setValue(PREFERENCE_SCROLLBARS_MODE, mode);
+ }
+
+ @Override
+ public int getScrollbarsMode() {
+ return getPreferenceStore().getInt(PREFERENCE_SCROLLBARS_MODE);
+ }
 }

org.eclipse.gef/src/org/eclipse/gef/ui/palette/PaletteMessages.java

@@ -236,6 +236,12 @@ public class PaletteMessages extends NLS {
  * The String "<Using Workbench Dialog Font>"
  */
  public static String SETTINGS_WORKBENCH_FONT_LABEL;
+ /**
+ * The String "Enable Overlay Scrolling"
+ *
+ * @since 3.20
+ */
+ public static String SETTINGS_OVERLAY_SCROLLING;
  /**
  * The String "-"
  */

org.eclipse.gef/src/org/eclipse/gef/ui/palette/PaletteViewer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2010 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -71,6 +71,11 @@ public void propertyChange(PropertyChangeEvent evt) {
  || property.equals(DefaultPaletteViewerPreferences
  .convertLayoutToPreferenceName(getPaletteViewerPreferences().getLayoutSetting()))) {
  refreshAllEditParts(root);
+ } else if (property.equals(PaletteViewerPreferences.PREFERENCE_SCROLLBARS_MODE)) {
+ FigureCanvas canvas = getFigureCanvas();
+ if (canvas != null) {
+ canvas.setScrollbarsMode((int) evt.getNewValue());
+ }
  }
  }
 
@@ -271,6 +276,7 @@ protected void hookControl() {
  canvas.setHorizontalScrollBarVisibility(FigureCanvas.NEVER);
  canvas.setVerticalScrollBarVisibility(globalScrollbar ? FigureCanvas.ALWAYS : FigureCanvas.AUTOMATIC);
  if (prefs != null) {
+ canvas.setScrollbarsMode(prefs.getScrollbarsMode());
  prefs.addPropertyChangeListener(prefListener);
  }
  updateFont();

org.eclipse.gef/src/org/eclipse/gef/ui/palette/PaletteViewerPreferences.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2010 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -14,6 +14,7 @@
 
 import java.beans.PropertyChangeListener;
 
+import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.FontData;
 
 /**
@@ -26,6 +27,7 @@
  * future.
  *
  * @author Pratik Shah
+ * @noimplement This interface is not intended to be implemented by clients.
  */
 public interface PaletteViewerPreferences {
 
@@ -129,6 +131,14 @@ public interface PaletteViewerPreferences {
  */
  String PREFERENCE_FONT = "Palette Font"; //$NON-NLS-1$
 
+ /**
+ * <b>Linux Only</b> Property name for enabling or disabling the scrollbars
+ * overlay.
+ *
+ * @since 3.20
+ */
+ String PREFERENCE_SCROLLBARS_MODE = "Scrollbars Mode"; //$NON-NLS-1$
+
  /**
  * @param listener the PropertyChangeListener to be notified of changes
  * @see java.beans.PropertyChangeSupport#addPropertyChangeListener(java.beans.PropertyChangeListener)
@@ -298,4 +308,25 @@ public interface PaletteViewerPreferences {
  */
  boolean useLargeIcons();
 
+ /**
+ * Enables or disables overlay scrolling for the palette viewer. Supported
+ * values are:
+ * <ul>
+ * <li>{@link SWT#NONE}</li>
+ * <li>{@link SWT#SCROLLBAR_OVERLAY}</li>
+ * </ul>
+ * Overlay scrollbars are only supported on {@code Linux}.
+ *
+ * @since 3.20
+ */
+ void setScrollbarsMode(int mode);
+
+ /**
+ * Returns whether overlay scrolling is enabled for the palette viewer . Overlay
+ * scrollbars are only supported on {@code Linux}.
+ *
+ * @return One of {@link SWT#SCROLLBAR_OVERLAY} or {@link SWT#NONE}.
+ * @since 3.20
+ */
+ int getScrollbarsMode();
 }

org.eclipse.gef/src/org/eclipse/gef/ui/palette/customize/PaletteSettingsDialog.java

@@ -20,6 +20,7 @@
 import org.eclipse.swt.graphics.FontData;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Button;
@@ -31,6 +32,7 @@
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Widget;
 
+import org.eclipse.core.runtime.Platform;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.resource.ImageDescriptor;
@@ -70,6 +72,10 @@ public class PaletteSettingsDialog extends Dialog {
  protected static final String CACHE_DETAILS_ICON_SIZE = "details - use large icons"; //$NON-NLS-1$
  protected static final String CACHE_FONT = "font"; //$NON-NLS-1$
  protected static final String CACHE_COLLAPSE = "auto-collapse setting"; //$NON-NLS-1$
+ /**
+ * @since 3.20
+ */
+ protected static final String CACHE_SCROLLBARS_MODE = "scrollbars mode"; //$NON-NLS-1$
 
  /**
  * The unique IDs for the various widgets. These IDs can be used to retrieve
@@ -90,6 +96,10 @@ public class PaletteSettingsDialog extends Dialog {
  protected static final int LAYOUT_DETAILS_VIEW_ID = IDialogConstants.CLIENT_ID + 12;
  protected static final int FONT_CHANGE_ID = IDialogConstants.CLIENT_ID + 13;
  protected static final int DEFAULT_FONT_ID = IDialogConstants.CLIENT_ID + 14;
+ /**
+ * @since 3.20
+ */
+ protected static final int SCROLLBARS_MODE_ID = IDialogConstants.CLIENT_ID + 15;
 
  /**
  * Sub - classes that need to create their own unique IDs should do so by adding
@@ -163,6 +173,9 @@ protected void buttonPressed(int buttonId) {
  case DEFAULT_FONT_ID:
  handleDefaultFontRequested();
  break;
+ case SCROLLBARS_MODE_ID:
+ handleScrollbarsModeChanged(b.getSelection());
+ break;
  default:
  super.buttonPressed(buttonId);
  break;
@@ -186,6 +199,7 @@ protected void cacheSettings() {
  settings.put(CACHE_COLUMNS_ICON_SIZE,
  Boolean.valueOf(prefs.useLargeIcons(PaletteViewerPreferences.LAYOUT_COLUMNS)));
  settings.put(CACHE_LIST_ICON_SIZE, Boolean.valueOf(prefs.useLargeIcons(PaletteViewerPreferences.LAYOUT_LIST)));
+ settings.put(CACHE_SCROLLBARS_MODE, prefs.getScrollbarsMode());
  }
 
  /**
@@ -348,6 +362,11 @@ protected Control createDialogArea(Composite parent) {
  data.horizontalIndent = 5;
  child.setLayoutData(data);
 
+ if (Platform.getOS().equals(Platform.OS_LINUX)) {
+ child = createScrollbarsSettings(composite);
+ child.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 2, 1));
+ }
+
  Label label = new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL);
  data = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
  data.horizontalSpan = 2;
@@ -436,6 +455,23 @@ protected Control createColumnsOptions(Composite parent) {
  return contents;
  }
 
+ /**
+ * Creates and initializes the part of the dialog that displays the options for
+ * overlay scrolling. This method should only be called on Linux. *
+ *
+ * @param parent the parent composite
+ * @return the newly created control
+ *
+ * @since 3.20
+ */
+ protected Control createScrollbarsSettings(Composite parent) {
+ Composite composite = new Composite(parent, SWT.NONE);
+ composite.setLayout(new FillLayout());
+ Button button = createButton(composite, SCROLLBARS_MODE_ID, "Enable overlay scrollbar", SWT.CHECK, null);
+ button.setSelection(prefs.getScrollbarsMode() == SWT.SCROLLBAR_OVERLAY);
+ return composite;
+ }
+
  /**
  * Creates and initializes (i.e. loads the current settings from
  * PaletteViewerPreferences) the part of the dialog that displays the font
@@ -734,6 +770,17 @@ protected void handleLayoutSettingChanged(int newSetting) {
  }
  }
 
+ /**
+ * This method is called whenever the "Enable Overlay Scrolling" checkbox is
+ * selected/deselected. The method argument is the new state of the button.
+ *
+ * @param checked If {@code true}, overlay scrolling will be enabled.
+ * @since 3.20
+ */
+ protected void handleScrollbarsModeChanged(boolean checked) {
+ prefs.setScrollbarsMode(checked ? SWT.SCROLLBAR_OVERLAY : SWT.NONE);
+ }
+
  /**
  * Restores the cached settings, thus undoing any changes made since the last
  * caching of settings.
@@ -752,6 +799,7 @@ protected void restoreSettings() {
  ((Boolean) settings.get(CACHE_LIST_ICON_SIZE)).booleanValue());
  prefs.setUseLargeIcons(PaletteViewerPreferences.LAYOUT_COLUMNS,
  ((Boolean) settings.get(CACHE_COLUMNS_ICON_SIZE)).booleanValue());
+ prefs.setScrollbarsMode((int) settings.get(CACHE_SCROLLBARS_MODE));
  }
 
  /**

org.eclipse.gef/src/org/eclipse/gef/ui/palette/messages.properties

@@ -22,6 +22,7 @@ SETTINGS_LIST_VIEW_LABEL=&List
 SETTINGS_USE_LARGE_ICONS_LABEL=&Use large icons
 SETTINGS_USE_LARGE_ICONS_LABEL_CAPS=&Use Large Icons
 SETTINGS_ICONS_VIEW_LABEL=&Icons only
+SETTINGS_OVERLAY_SCROLLING=Enable Overlay Scrolling
 COLLAPSE_NEVER_LABEL=&Never close
 COLLAPSE_ALWAYS_LABEL=&Always close when opening another drawer
 COLLAPSE_AS_NEEDED_LABEL=Close automatically &when there is not enough room