Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2010 IBM Corporation and others. * 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: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.ui.internal.texteditor; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StyledText; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.FocusListener; import org.eclipse.swt.events.KeyEvent; import org.eclipse.swt.events.KeyListener; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Shell; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.text.BadLocationException; import org.eclipse.jface.text.Document; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.IInformationControl; import org.eclipse.jface.text.IInformationControlCreator; import org.eclipse.jface.text.IInformationControlExtension; import org.eclipse.jface.text.IInformationControlExtension3; import org.eclipse.jface.text.IInformationControlExtension5; import org.eclipse.jface.text.IRegion; import org.eclipse.jface.text.source.SourceViewer; import org.eclipse.ui.internal.editors.text.EditorsPlugin; import org.eclipse.ui.editors.text.TextSourceViewerConfiguration; /** * Source viewer based implementation of <code>IInformationControl</code>. * Displays information in a source viewer configured with the text editor * preference store. * * @since 3.0 */ class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, IInformationControlExtension3, IInformationControlExtension5, DisposeListener { /** The control's shell */ private Shell fShell; /** The control's text widget */ private StyledText fText; /** The symbolic font name of the text font */ private final String fSymbolicFontName; /** The text font (do not dispose!) */ private Font fTextFont; /** The control's source viewer */ private SourceViewer fViewer; /** The optional status field. */ private Label fStatusField; /** The separator for the optional status field. */ private Label fSeparator; /** The font of the optional status text label.*/ private Font fStatusTextFont; /** * The color of the optional status text label or <code>null</code> if none. * * @since 3.6 */ private Color fStatusTextForegroundColor; /** The maximal widget width. */ private int fMaxWidth; /** The maximal widget height. */ private int fMaxHeight; /** The horizontal scroll index. */ private int fHorizontalScrollPixel; /** * Creates a source viewer information control with the given shell as * parent. The given shell styles are applied to the created shell. The * given styles are applied to the created styled text widget. The text * widget will be initialized with the given font. The status field will * contain the given text or be hidden. * * @param parent the parent shell * @param isResizable <code>true</code> if resizable * @param symbolicFontName the symbolic font name * @param statusFieldText the text to be used in the optional status field * or <code>null</code> if the status field should be hidden */ public SourceViewerInformationControl(Shell parent, boolean isResizable, String symbolicFontName, String statusFieldText) { GridLayout layout; GridData gd; int shellStyle = SWT.TOOL | SWT.ON_TOP | (isResizable ? SWT.RESIZE : 0); int textStyle = isResizable ? SWT.V_SCROLL | SWT.H_SCROLL : SWT.NONE; fShell = new Shell(parent, shellStyle); Display display = fShell.getDisplay(); Composite composite = fShell; layout = new GridLayout(1, false); layout.marginHeight = 0; layout.marginWidth = 0; composite.setLayout(layout); gd = new GridData(GridData.FILL_HORIZONTAL); composite.setLayoutData(gd); if (statusFieldText != null) { composite = new Composite(composite, SWT.NONE); layout = new GridLayout(1, false); layout.marginHeight = 0; layout.marginWidth = 0; composite.setLayout(layout); gd = new GridData(GridData.FILL_BOTH); composite.setLayoutData(gd); composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND)); composite.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND)); } // Source viewer fViewer = new SourceViewer(composite, null, textStyle); fViewer.configure(new TextSourceViewerConfiguration(EditorsPlugin.getDefault().getPreferenceStore())); fViewer.setEditable(false); fText = fViewer.getTextWidget(); gd = new GridData(GridData.BEGINNING | GridData.FILL_BOTH); fText.setLayoutData(gd); fText.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND)); fText.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND)); fSymbolicFontName = symbolicFontName; fTextFont = JFaceResources.getFont(symbolicFontName); fText.setFont(fTextFont); fText.addKeyListener(new KeyListener() { public void keyPressed(KeyEvent e) { if (e.character == 0x1B) // ESC fShell.dispose(); } public void keyReleased(KeyEvent e) { } }); // Status field if (statusFieldText != null) { // Horizontal separator line fSeparator = new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL | SWT.LINE_DOT); fSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); // Status field label fStatusField = new Label(composite, SWT.RIGHT); fStatusField.setText(statusFieldText); Font font = fStatusField.getFont(); FontData[] fontDatas = font.getFontData(); for (int i = 0; i < fontDatas.length; i++) fontDatas[i].setHeight(fontDatas[i].getHeight() * 9 / 10); fStatusTextFont = new Font(fStatusField.getDisplay(), fontDatas); fStatusField.setFont(fStatusTextFont); GridData gd2 = new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL | GridData.HORIZONTAL_ALIGN_BEGINNING | GridData.VERTICAL_ALIGN_BEGINNING); fStatusField.setLayoutData(gd2); fStatusTextForegroundColor = new Color(fStatusField.getDisplay(), blend(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB(), display.getSystemColor(SWT.COLOR_INFO_FOREGROUND).getRGB(), 0.56f)); fStatusField.setForeground(fStatusTextForegroundColor); fStatusField.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND)); } addDisposeListener(this); } /** * Returns an RGB that lies between the given foreground and background * colors using the given mixing factor. A <code>factor</code> of 1.0 will produce a * color equal to <code>fg</code>, while a <code>factor</code> of 0.0 will produce one * equal to <code>bg</code>. * @param bg the background color * @param fg the foreground color * @param factor the mixing factor, must be in [0, 1] * * @return the interpolated color * @since 3.6 */ private static RGB blend(RGB bg, RGB fg, float factor) { // copy of org.eclipse.jface.internal.text.revisions.Colors#blend(..) Assert.isLegal(bg != null); Assert.isLegal(fg != null); Assert.isLegal(factor >= 0f && factor <= 1f); float complement = 1f - factor; return new RGB((int) (complement * bg.red + factor * fg.red), (int) (complement * bg.green + factor * fg.green), (int) (complement * bg.blue + factor * fg.blue)); } /* * @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object) */ public void setInput(Object input) { if (input instanceof String) setInformation((String) input); else setInformation(null); } /* * @see IInformationControl#setInformation(String) */ public void setInformation(String content) { if (content == null) { fViewer.setInput(null); return; } IDocument doc = new Document(content); fViewer.setInput(doc); // ensure that we can scroll enough ensureScrollable(); fViewer.getTextWidget().setHorizontalPixel(fHorizontalScrollPixel); } /* * @see IInformationControl#setVisible(boolean) */ public void setVisible(boolean visible) { fShell.setVisible(visible); } /* * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent) */ public void widgetDisposed(DisposeEvent event) { if (fStatusTextFont != null && !fStatusTextFont.isDisposed()) fStatusTextFont.dispose(); fStatusTextFont = null; if (fStatusTextForegroundColor != null && !fStatusTextForegroundColor.isDisposed()) fStatusTextForegroundColor.dispose(); fStatusTextForegroundColor = null; fTextFont = null; fShell = null; fText = null; } /* * @see org.eclipse.jface.text.IInformationControl#dispose() */ public final void dispose() { if (fShell != null && !fShell.isDisposed()) fShell.dispose(); else widgetDisposed(null); } /* * @see IInformationControl#setSize(int, int) */ public void setSize(int width, int height) { if (fStatusField != null) { GridData gd = (GridData) fViewer.getTextWidget().getLayoutData(); Point statusSize = fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); Point separatorSize = fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); gd.heightHint = height - statusSize.y - separatorSize.y; } fShell.setSize(width, height); if (fStatusField != null) fShell.pack(true); } /* * @see IInformationControl#setLocation(Point) */ public void setLocation(Point location) { fShell.setLocation(location); } /* * @see IInformationControl#setSizeConstraints(int, int) */ public void setSizeConstraints(int maxWidth, int maxHeight) { fMaxWidth = maxWidth; fMaxHeight = maxHeight; } /* * @see IInformationControl#computeSizeHint() */ public Point computeSizeHint() { // compute the preferred size int x = SWT.DEFAULT; int y = SWT.DEFAULT; Point size = fShell.computeSize(x, y); if (size.x > fMaxWidth) x = fMaxWidth; if (size.y > fMaxHeight) y = fMaxHeight; // recompute using the constraints if the preferred size is larger than the constraints if (x != SWT.DEFAULT || y != SWT.DEFAULT) size = fShell.computeSize(x, y, false); return size; } /* * @see IInformationControl#addDisposeListener(DisposeListener) */ public void addDisposeListener(DisposeListener listener) { fShell.addDisposeListener(listener); } /* * @see IInformationControl#removeDisposeListener(DisposeListener) */ public void removeDisposeListener(DisposeListener listener) { fShell.removeDisposeListener(listener); } /* * @see IInformationControl#setForegroundColor(Color) */ public void setForegroundColor(Color foreground) { fText.setForeground(foreground); } /* * @see IInformationControl#setBackgroundColor(Color) */ public void setBackgroundColor(Color background) { fText.setBackground(background); } /* * @see IInformationControl#isFocusControl() */ public boolean isFocusControl() { return fShell.getDisplay().getActiveShell() == fShell; } /* * @see IInformationControl#setFocus() */ public void setFocus() { fShell.forceFocus(); fText.setFocus(); } /* * @see IInformationControl#addFocusListener(FocusListener) */ public void addFocusListener(FocusListener listener) { fText.addFocusListener(listener); } /* * @see IInformationControl#removeFocusListener(FocusListener) */ public void removeFocusListener(FocusListener listener) { fText.removeFocusListener(listener); } /* * @see IInformationControlExtension#hasContents() */ public boolean hasContents() { return fText.getCharCount() > 0; } /** * @param scrollIndex the new horizontal scroll index. */ void setHorizontalScrollPixel(int scrollIndex) { scrollIndex = Math.max(0, scrollIndex); fHorizontalScrollPixel = scrollIndex; } /** * Ensures that the control can be scrolled at least to * <code>fHorizontalScrollPixel</code> and adjusts <code>fMaxWidth</code> * accordingly. * * @since 3.3 */ private void ensureScrollable() { IDocument doc = fViewer.getDocument(); if (doc == null) return; StyledText widget = fViewer.getTextWidget(); if (widget == null || widget.isDisposed()) return; int last = doc.getNumberOfLines() - 1; GC gc = new GC(widget); gc.setFont(widget.getFont()); int maxWidth = 0; String content = new String(); try { for (int i = 0; i <= last; i++) { IRegion line; line = doc.getLineInformation(i); content = doc.get(line.getOffset(), line.getLength()); int width = gc.textExtent(content).x; if (width > maxWidth) { maxWidth = width; } } } catch (BadLocationException e) { return; } finally { gc.dispose(); } // limit the size of the window to the maximum width minus scrolling, // but never more than the configured max size (viewport size). fMaxWidth = Math.max(0, Math.min(fMaxWidth, maxWidth - fHorizontalScrollPixel + 8)); } /* * @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim() * @since 3.4 */ public Rectangle computeTrim() { Rectangle trim = fShell.computeTrim(0, 0, 0, 0); addInternalTrim(trim); return trim; } /** * Adds the internal trimmings to the given trim of the shell. * * @param trim the shell's trim, will be updated * @since 3.4 */ private void addInternalTrim(Rectangle trim) { if (fStatusField != null) { trim.height += fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y; trim.height += fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y; } } /* * @see org.eclipse.jface.text.IInformationControlExtension3#getBounds() * @since 3.4 */ public Rectangle getBounds() { return fShell.getBounds(); } /* * @see org.eclipse.jface.text.IInformationControlExtension3#restoresLocation() * @since 3.4 */ public boolean restoresLocation() { return false; } /* * @see org.eclipse.jface.text.IInformationControlExtension3#restoresSize() * @since 3.4 */ public boolean restoresSize() { return false; } /* * @see org.eclipse.jface.text.IInformationControlExtension5#getInformationPresenterControlCreator() * @since 3.4 */ public IInformationControlCreator getInformationPresenterControlCreator() { return new IInformationControlCreator() { public IInformationControl createInformationControl(Shell parent) { return new SourceViewerInformationControl(parent, true, fSymbolicFontName, null); } }; } /* * @see org.eclipse.jface.text.IInformationControlExtension5#containsControl(org.eclipse.swt.widgets.Control) * @since 3.4 */ public boolean containsControl(Control control) { do { if (control == fShell) return true; if (control instanceof Shell) return false; control = control.getParent(); } while (control != null); return false; } /* * @see org.eclipse.jface.text.IInformationControlExtension5#isVisible() * @since 3.4 */ public boolean isVisible() { return fShell != null && !fShell.isDisposed() && fShell.isVisible(); } /* * @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int) * @since 3.4 */ public Point computeSizeConstraints(int widthInChars, int heightInChars) { GC gc = new GC(fText); gc.setFont(fTextFont); int width = gc.getFontMetrics().getAverageCharWidth(); int height = gc.getFontMetrics().getHeight(); gc.dispose(); return new Point(widthInChars * width, heightInChars * height); } }