Add diff viewer that uses theme and editors settings.refs/changes/49/3149/10

The DiffViewer class uses theme settings for added,
removed, and hunk lines, and editor settings for
font and foreground, background, selection, and line
highlight colors.  It also supports displaying a line
number column in the overview ruler.

Bug: 343000
Change-Id: I75be7310b9f4a66a8d5a392a09fe66795110c0a3
Signed-off-by: Kevin Sawicki <kevin@github.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

2 files changed, 247 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIPreferences.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIPreferences.java
index 9e50401..35f9615 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIPreferences.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIPreferences.java
@@ -70,6 +70,18 @@ public class UIPreferences {
 	public final static String THEME_UncommittedChangeBackgroundColor = "org.eclipse.egit.ui.UncommittedChangeBackgroundColor"; //$NON-NLS-1$
 	/** */
 	public final static String THEME_UncommittedChangeFont = "org.eclipse.egit.ui.UncommittedChangeFont"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffHunkBackgroundColor = "org.eclipse.egit.ui.DiffHunkBackgroundColor"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffHunkForegroundColor = "org.eclipse.egit.ui.DiffHunkForegroundColor"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffAddBackgroundColor = "org.eclipse.egit.ui.DiffAddBackgroundColor"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffAddForegroundColor = "org.eclipse.egit.ui.DiffAddForegroundColor"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffRemoveBackgroundColor = "org.eclipse.egit.ui.DiffRemoveBackgroundColor"; //$NON-NLS-1$
+	/** */
+	public final static String THEME_DiffRemoveForegroundColor = "org.eclipse.egit.ui.DiffRemoveForegroundColor"; //$NON-NLS-1$
 
 	/** */
 	public final static String DECORATOR_RECOMPUTE_ANCESTORS = "decorator_recompute_ancestors"; //$NON-NLS-1$
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java
new file mode 100644
index 0000000..f2e00b5
--- a/dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java
@@ -0,0 +1,235 @@
+/*******************************************************************************
+ *  Copyright (c) 2011 GitHub Inc.
+ *  All rights reserved. This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License v1.0
+ *  which accompanies this distribution, and is available at
+ *  http://www.eclipse.org/legal/epl-v10.html
+ *
+ *  Contributors:
+ *    Kevin Sawicki (GitHub Inc.) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.egit.ui.internal.commit;
+
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffAddBackgroundColor;
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffAddForegroundColor;
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffHunkBackgroundColor;
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffHunkForegroundColor;
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffRemoveBackgroundColor;
+import static org.eclipse.egit.ui.UIPreferences.THEME_DiffRemoveForegroundColor;
+
+import org.eclipse.egit.ui.internal.commit.DiffStyleRangeFormatter.DiffStyleRange;
+import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.jface.preference.PreferenceConverter;
+import org.eclipse.jface.resource.ColorDescriptor;
+import org.eclipse.jface.resource.ColorRegistry;
+import org.eclipse.jface.resource.DeviceResourceManager;
+import org.eclipse.jface.resource.JFaceResources;
+import org.eclipse.jface.text.Document;
+import org.eclipse.jface.text.source.CompositeRuler;
+import org.eclipse.jface.text.source.IVerticalRuler;
+import org.eclipse.jface.text.source.LineNumberRulerColumn;
+import org.eclipse.jface.text.source.SourceViewer;
+import org.eclipse.jface.util.IPropertyChangeListener;
+import org.eclipse.jface.util.PropertyChangeEvent;
+import org.eclipse.swt.custom.LineBackgroundEvent;
+import org.eclipse.swt.custom.LineBackgroundListener;
+import org.eclipse.swt.custom.StyleRange;
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.events.DisposeEvent;
+import org.eclipse.swt.events.DisposeListener;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.editors.text.EditorsUI;
+import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
+import org.eclipse.ui.texteditor.AbstractTextEditor;
+import org.eclipse.ui.texteditor.SourceViewerDecorationSupport;
+import org.eclipse.ui.themes.IThemeManager;
+
+/**
+ * Source viewer to display one or more file differences using standard editor
+ * colors and fonts preferences.
+ */
+public class DiffViewer extends SourceViewer {
+
+	private DiffStyleRangeFormatter formatter;
+
+	private DeviceResourceManager colors = new DeviceResourceManager(PlatformUI
+			.getWorkbench().getDisplay());
+
+	private LineNumberRulerColumn lineNumberRuler;
+
+	private Color hunkBackgroundColor;
+
+	private Color hunkForegroundColor;
+
+	private Color addBackgroundColor;
+
+	private Color addForegroundColor;
+
+	private Color removeBackgroundColor;
+
+	private Color removeForegroundColor;
+
+	private IPropertyChangeListener themeListener = new IPropertyChangeListener() {
+
+		public void propertyChange(PropertyChangeEvent event) {
+			String property = event.getProperty();
+			if (IThemeManager.CHANGE_CURRENT_THEME.equals(property)
+					|| THEME_DiffAddBackgroundColor.equals(property)
+					|| THEME_DiffAddForegroundColor.equals(property)
+					|| THEME_DiffHunkBackgroundColor.equals(property)
+					|| THEME_DiffHunkForegroundColor.equals(property)
+					|| THEME_DiffRemoveBackgroundColor.equals(property)
+					|| THEME_DiffRemoveForegroundColor.equals(property)) {
+				refreshDiffColors();
+				refreshStyleRanges();
+			}
+		}
+	};
+
+	private IPropertyChangeListener editorPrefListener = new IPropertyChangeListener() {
+
+		public void propertyChange(PropertyChangeEvent event) {
+			styleViewer();
+		}
+	};
+
+	/**
+	 * @param parent
+	 * @param ruler
+	 * @param styles
+	 */
+	public DiffViewer(Composite parent, IVerticalRuler ruler, int styles) {
+		super(parent, ruler, styles);
+		setDocument(new Document());
+		SourceViewerDecorationSupport support = new SourceViewerDecorationSupport(
+				this, null, null, EditorsUI.getSharedTextColors());
+		support.setCursorLinePainterPreferenceKeys(
+				AbstractDecoratedTextEditorPreferenceConstants.EDITOR_CURRENT_LINE,
+				AbstractDecoratedTextEditorPreferenceConstants.EDITOR_CURRENT_LINE_COLOR);
+		support.install(EditorsUI.getPreferenceStore());
+		if (ruler instanceof CompositeRuler) {
+			lineNumberRuler = new LineNumberRulerColumn();
+			((CompositeRuler) ruler).addDecorator(0, lineNumberRuler);
+		}
+		initListeners();
+		getControl().addDisposeListener(new DisposeListener() {
+
+			public void widgetDisposed(DisposeEvent e) {
+				EditorsUI.getPreferenceStore().removePropertyChangeListener(
+						editorPrefListener);
+				PlatformUI.getWorkbench().getThemeManager()
+						.removePropertyChangeListener(themeListener);
+				colors.dispose();
+			}
+		});
+		refreshDiffColors();
+		styleViewer();
+	}
+
+	private void refreshDiffColors() {
+		ColorRegistry reg = PlatformUI.getWorkbench().getThemeManager()
+				.getCurrentTheme().getColorRegistry();
+		this.addBackgroundColor = reg.get(THEME_DiffAddBackgroundColor);
+		this.addForegroundColor = reg.get(THEME_DiffAddForegroundColor);
+		this.removeBackgroundColor = reg.get(THEME_DiffRemoveBackgroundColor);
+		this.removeForegroundColor = reg.get(THEME_DiffRemoveForegroundColor);
+		this.hunkBackgroundColor = reg.get(THEME_DiffHunkBackgroundColor);
+		this.hunkForegroundColor = reg.get(THEME_DiffHunkForegroundColor);
+	}
+
+	private void initListeners() {
+		PlatformUI.getWorkbench().getThemeManager()
+				.addPropertyChangeListener(this.themeListener);
+		EditorsUI.getPreferenceStore().addPropertyChangeListener(
+				this.editorPrefListener);
+		getTextWidget().addLineBackgroundListener(new LineBackgroundListener() {
+
+			public void lineGetBackground(LineBackgroundEvent event) {
+				StyledText text = getTextWidget();
+				if (event.lineOffset < text.getCharCount()) {
+					StyleRange style = text
+							.getStyleRangeAtOffset(event.lineOffset);
+					if (style instanceof DiffStyleRange)
+						event.lineBackground = ((DiffStyleRange) style).lineBackground;
+				}
+			}
+		});
+	}
+
+	private ColorDescriptor createEditorColorDescriptor(String key) {
+		return ColorDescriptor.createFrom(PreferenceConverter.getColor(
+				EditorsUI.getPreferenceStore(), key));
+	}
+
+	private Color getEditorColor(String key) {
+		return (Color) colors.get(createEditorColorDescriptor(key));
+	}
+
+	private void styleViewer() {
+		IPreferenceStore store = EditorsUI.getPreferenceStore();
+		Color foreground = null;
+		if (!store
+				.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT))
+			foreground = getEditorColor(AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND);
+
+		Color background = null;
+		if (!store
+				.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT))
+			background = getEditorColor(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
+
+		Color selectionForeground = null;
+		if (!store
+				.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_SELECTION_FOREGROUND_SYSTEM_DEFAULT))
+			selectionForeground = getEditorColor(AbstractTextEditor.PREFERENCE_COLOR_SELECTION_FOREGROUND);
+
+		Color selectionBackground = null;
+		if (!store
+				.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_SELECTION_BACKGROUND_SYSTEM_DEFAULT))
+			selectionBackground = getEditorColor(AbstractTextEditor.PREFERENCE_COLOR_SELECTION_BACKGROUND);
+
+		StyledText text = getTextWidget();
+		text.setForeground(foreground);
+		text.setBackground(background);
+		text.setSelectionForeground(selectionForeground);
+		text.setSelectionBackground(selectionBackground);
+		text.setFont(JFaceResources.getFont(JFaceResources.TEXT_FONT));
+		if (lineNumberRuler != null) {
+			lineNumberRuler.setFont(text.getFont());
+			lineNumberRuler.setForeground(foreground);
+			lineNumberRuler.setBackground(background);
+		}
+	}
+
+	/** Refresh style ranges */
+	public void refreshStyleRanges() {
+		DiffStyleRange[] ranges = formatter != null ? formatter.getRanges()
+				: new DiffStyleRange[0];
+		for (DiffStyleRange range : ranges)
+			switch (range.diffType) {
+			case ADD:
+				range.foreground = addForegroundColor;
+				range.lineBackground = addBackgroundColor;
+				break;
+			case REMOVE:
+				range.foreground = removeForegroundColor;
+				range.lineBackground = removeBackgroundColor;
+				break;
+			case HUNK:
+				range.foreground = hunkForegroundColor;
+				range.lineBackground = hunkBackgroundColor;
+				break;
+			default:
+				break;
+			}
+		getTextWidget().setStyleRanges(ranges);
+	}
+
+	/** @param formatter */
+	public void setFormatter(DiffStyleRangeFormatter formatter) {
+		this.formatter = formatter;
+		refreshStyleRanges();
+	}
+
+}