Java tutorial
/* * Copyright (c) 2013, the Dart project authors. * * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except * in compliance with the License. You may obtain a copy of the License at * * http://www.eclipse.org/legal/epl-v10.html * * Unless required by applicable law or agreed to in writing, software distributed under the License * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express * or implied. See the License for the specific language governing permissions and limitations under * the License. */ package com.google.dart.tools.ui.web.yaml; import com.google.dart.tools.ui.PreferenceConstants; import org.eclipse.jface.action.IAction; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.text.ITextViewerExtension; import org.eclipse.jface.text.source.ISourceViewer; import org.eclipse.jface.text.source.IVerticalRulerExtension; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.ISelectionProvider; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StyledText; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.PaletteData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.widgets.Caret; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.ui.IEditorInput; import org.eclipse.ui.texteditor.ITextEditorActionConstants; /** * An editor used for the source tab in Pubspec forms editor */ public class PubspecYamlEditor extends YamlEditor { class FontPropertyChangeListener implements IPropertyChangeListener { @Override public void propertyChange(PropertyChangeEvent event) { if (getSourceViewer() == null) { return; } String property = event.getProperty(); if (PreferenceConstants.EDITOR_TEXT_FONT.equals(property)) { initializeViewerFont(getSourceViewer()); updateCaret(); return; } } } private IPropertyChangeListener fontPropertyChangeListener = new FontPropertyChangeListener(); private static final int WIDE_CARET_WIDTH = 2; private static final int SINGLE_CARET_WIDTH = 1; private Caret nonDefaultCaret; private Image nonDefaultCaretImage; private Caret initialCaret; @Override public void createPartControl(Composite parent) { super.createPartControl(parent); initialCaret = getSourceViewer().getTextWidget().getCaret(); initializeViewerFont(getSourceViewer()); updateCaret(); JFaceResources.getFontRegistry().addListener(fontPropertyChangeListener); } @Override public void dispose() { super.dispose(); if (fontPropertyChangeListener != null) { JFaceResources.getFontRegistry().removeListener(fontPropertyChangeListener); } fontPropertyChangeListener = null; initialCaret = null; } @Override protected void handleInsertModeChanged() { updateInsertModeAction(); updateCaret(); updateStatusField(ITextEditorActionConstants.STATUS_CATEGORY_INPUT_MODE); } @Override protected boolean isPubspecEditor() { IEditorInput input = getEditorInput(); if (input != null) { return "pubspec.yaml".equals(input.getName()); } else { return false; } } private Caret createInsertCaret(StyledText styledText) { Caret caret = new Caret(styledText, SWT.NULL); caret.setSize(getCaretWidthPreference(), styledText.getLineHeight()); caret.setFont(styledText.getFont()); return caret; } private Caret createOverwriteCaret(StyledText styledText) { Caret caret = new Caret(styledText, SWT.NULL); GC gc = new GC(styledText); Point charSize = gc.stringExtent("a"); //$NON-NLS-1$ caret.setSize(charSize.x, styledText.getLineHeight()); caret.setFont(styledText.getFont()); gc.dispose(); return caret; } private Caret createRawInsertModeCaret(StyledText styledText) { if (!getLegalInsertModes().contains(SMART_INSERT)) { return createInsertCaret(styledText); } Caret caret = new Caret(styledText, SWT.NULL); Image image = createRawInsertModeCaretImage(styledText); if (image != null) { caret.setImage(image); } else { caret.setSize(getCaretWidthPreference(), styledText.getLineHeight()); } caret.setFont(styledText.getFont()); return caret; } private Image createRawInsertModeCaretImage(StyledText styledText) { PaletteData caretPalette = new PaletteData(new RGB[] { new RGB(0, 0, 0), new RGB(255, 255, 255) }); int width = getCaretWidthPreference(); int widthOffset = width - 1; ImageData imageData = new ImageData(4 + widthOffset, styledText.getLineHeight(), 1, caretPalette); Display display = styledText.getDisplay(); Image bracketImage = new Image(display, imageData); GC gc = new GC(bracketImage); gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE)); gc.setLineWidth(0); // NOTE: 0 means width is 1 but with optimized performance int height = imageData.height / 3; for (int i = 0; i < width; i++) { gc.drawLine(i, 0, i, height - 1); gc.drawLine(i, imageData.height - height, i, imageData.height - 1); } gc.dispose(); return bracketImage; } private void disposeNonDefaultCaret() { if (nonDefaultCaretImage != null) { nonDefaultCaretImage.dispose(); nonDefaultCaretImage = null; } if (nonDefaultCaret != null) { nonDefaultCaret.dispose(); nonDefaultCaret = null; } } private int getCaretWidthPreference() { if (getPreferenceStore() != null && getPreferenceStore().getBoolean(PREFERENCE_WIDE_CARET)) { return WIDE_CARET_WIDTH; } return SINGLE_CARET_WIDTH; } private void initializeViewerFont(ISourceViewer viewer) { Font font = null; String symbolicFontName = PreferenceConstants.EDITOR_TEXT_FONT; font = JFaceResources.getFont(symbolicFontName); if (font == null) { font = JFaceResources.getTextFont(); } if (!font.equals(getSourceViewer().getTextWidget().getFont())) { setFont(viewer, font); } else { font.dispose(); } } private void setFont(ISourceViewer sourceViewer, Font font) { if (sourceViewer.getDocument() != null) { ISelectionProvider provider = sourceViewer.getSelectionProvider(); ISelection selection = provider.getSelection(); int topIndex = sourceViewer.getTopIndex(); StyledText styledText = sourceViewer.getTextWidget(); Control parent = styledText; if (sourceViewer instanceof ITextViewerExtension) { ITextViewerExtension extension = (ITextViewerExtension) sourceViewer; parent = extension.getControl(); } parent.setRedraw(false); styledText.setFont(font); if (getVerticalRuler() instanceof IVerticalRulerExtension) { IVerticalRulerExtension e = (IVerticalRulerExtension) getVerticalRuler(); e.setFont(font); } provider.setSelection(selection); sourceViewer.setTopIndex(topIndex); if (parent instanceof Composite) { Composite composite = (Composite) parent; composite.layout(true); } parent.setRedraw(true); } else { StyledText styledText = sourceViewer.getTextWidget(); styledText.setFont(font); if (getVerticalRuler() instanceof IVerticalRulerExtension) { IVerticalRulerExtension e = (IVerticalRulerExtension) getVerticalRuler(); e.setFont(font); } } } private void updateCaret() { if (getSourceViewer() == null) { return; } StyledText styledText = getSourceViewer().getTextWidget(); InsertMode mode = getInsertMode(); styledText.setCaret(null); disposeNonDefaultCaret(); if (!isInInsertMode()) { nonDefaultCaret = createOverwriteCaret(styledText); } else if (SMART_INSERT == mode) { nonDefaultCaret = createInsertCaret(styledText); } else if (INSERT == mode) { nonDefaultCaret = createRawInsertModeCaret(styledText); } if (nonDefaultCaret != null) { styledText.setCaret(nonDefaultCaret); nonDefaultCaretImage = nonDefaultCaret.getImage(); } else if (initialCaret != styledText.getCaret()) { styledText.setCaret(initialCaret); } } private void updateInsertModeAction() { if (getSite() == null) { return; } IAction action = getAction(ITextEditorActionConstants.TOGGLE_INSERT_MODE); if (action != null) { action.setEnabled(isInInsertMode()); action.setChecked(getInsertMode() == SMART_INSERT); } } }