Java tutorial
/******************************************************************************* * Copyright (c) 2007 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: * Stefan Xenos, IBM Corporation - initial API and implementation * Chris Torrence, ITT Visual Information Solutions - initial API and implementation (bug 51580) *******************************************************************************/ package org.eclipse.ui.tests.layout.constraints; import org.eclipse.jface.dialogs.MessageDialog; import org.eclipse.jface.layout.GridDataFactory; import org.eclipse.jface.layout.GridLayoutFactory; import org.eclipse.jface.layout.LayoutConstants; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Text; import org.eclipse.ui.ISizeProvider; import org.eclipse.ui.IWorkbenchPage; import org.eclipse.ui.IWorkbenchPartConstants; import org.eclipse.ui.PartInitException; import org.eclipse.ui.part.ViewPart; public class LayoutConstraintsView extends ViewPart implements ISizeProvider { private Control control; private int minWidth = ISizeProvider.INFINITE; private int maxWidth = ISizeProvider.INFINITE; private int minHeight = ISizeProvider.INFINITE; private int maxHeight = ISizeProvider.INFINITE; private int quantizedWidth = ISizeProvider.INFINITE; private int quantizedHeight = ISizeProvider.INFINITE; private int fixedArea = ISizeProvider.INFINITE; private Text minWidthText; private Text maxWidthText; private Text quantizedWidthText; private Text minHeightText; private Text maxHeightText; private Text quantizedHeightText; private Text fixedAreaText; private Text sampleImplementation; public void createPartControl(Composite parent) { control = parent; Composite buttonBar = new Composite(parent, SWT.NONE); { GridDataFactory buttonData = GridDataFactory.fillDefaults().grab(true, false); Button applyButton = new Button(buttonBar, SWT.PUSH); applyButton.setText("Apply"); applyButton.addSelectionListener(new SelectionAdapter() { /* (non-Javadoc) * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent) */ public void widgetSelected(SelectionEvent e) { applyPressed(); } }); buttonData.applyTo(applyButton); Button clearButton = new Button(buttonBar, SWT.PUSH); clearButton.setText("Reset"); clearButton.addSelectionListener(new SelectionAdapter() { /* (non-Javadoc) * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent) */ public void widgetSelected(SelectionEvent e) { minWidthText.setText(""); maxWidthText.setText(""); quantizedWidthText.setText(""); minHeightText.setText(""); maxHeightText.setText(""); quantizedHeightText.setText(""); fixedAreaText.setText(""); applyPressed(); } }); buttonData.applyTo(clearButton); Button newViewButton = new Button(buttonBar, SWT.PUSH); newViewButton.setText("New View"); newViewButton.addSelectionListener(new SelectionAdapter() { /* (non-Javadoc) * @see org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse.swt.events.SelectionEvent) */ public void widgetSelected(SelectionEvent e) { try { getSite().getPage().showView( "org.eclipse.ui.tests.layout.constraints.LayoutConstraintsView", "" + System.currentTimeMillis(), IWorkbenchPage.VIEW_ACTIVATE); } catch (PartInitException e1) { MessageDialog.openError(getSite().getShell(), "Error opening view", "Unable to open view."); } } }); buttonData.applyTo(newViewButton); GridLayoutFactory.fillDefaults().equalWidth(true).numColumns(3).applyTo(buttonBar); } GridDataFactory.fillDefaults().grab(true, false).span(2, 1).applyTo(buttonBar); new Label(parent, SWT.NONE).setText("Min Width"); minWidthText = createText(parent); new Label(parent, SWT.NONE).setText("Max Width (blank = unbounded)"); maxWidthText = createText(parent); new Label(parent, SWT.NONE).setText("Quantized Width (blank = none)"); quantizedWidthText = createText(parent); new Label(parent, SWT.NONE).setText("Min Height"); minHeightText = createText(parent); new Label(parent, SWT.NONE).setText("Max Height (blank = unbounded)"); maxHeightText = createText(parent); new Label(parent, SWT.NONE).setText("Quantized Height (blank = none)"); quantizedHeightText = createText(parent); new Label(parent, SWT.NONE).setText("Fixed Area (blank = none"); fixedAreaText = createText(parent); sampleImplementation = new Text(parent, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL); sampleImplementation.setFont(JFaceResources.getFont(JFaceResources.TEXT_FONT)); sampleImplementation.setTabs(4); GridDataFactory.fillDefaults().grab(true, true).span(2, 1).applyTo(sampleImplementation); GridLayoutFactory.fillDefaults().numColumns(2).margins(LayoutConstants.getMargins()).generateLayout(parent); applyPressed(); } /** * */ protected void applyPressed() { // Copy the values from the text boxes minWidth = getInt(minWidthText); maxWidth = getInt(maxWidthText); quantizedWidth = getInt(quantizedWidthText); minHeight = getInt(minHeightText); maxHeight = getInt(maxHeightText); quantizedHeight = getInt(quantizedHeightText); fixedArea = getInt(fixedAreaText); StringBuffer result = new StringBuffer(); result.append("// Sample implementation: Make sure your ViewPart adapts to ISizeProvider.\n"); result.append("// Then implement the following two methods.\n\n"); sampleImplementation.setText(result.toString() + getSizeFlagsString() + computePreferredSizeString()); // Trigger a workbench layout updateLayout(); } /* (non-Javadoc) * @see org.eclipse.ui.ISizeProvider#getSizeFlags(boolean) */ public int getSizeFlags(boolean width) { int flags = 0; if (width) { if (minWidth != ISizeProvider.INFINITE) { flags |= SWT.MIN; } if (maxWidth != ISizeProvider.INFINITE) { flags |= SWT.MAX; } if (quantizedWidth != ISizeProvider.INFINITE || fixedArea != ISizeProvider.INFINITE) { flags |= SWT.FILL; } if (fixedArea != ISizeProvider.INFINITE) { flags |= SWT.WRAP; } } else { if (minHeight != ISizeProvider.INFINITE) { flags |= SWT.MIN; } if (maxHeight != ISizeProvider.INFINITE) { flags |= SWT.MAX; } if (quantizedHeight != ISizeProvider.INFINITE || fixedArea != ISizeProvider.INFINITE) { flags |= SWT.FILL; } if (fixedArea != ISizeProvider.INFINITE) { flags |= SWT.WRAP; } } return flags; } public String getSizeFlagsString() { StringBuffer result = new StringBuffer(); result.append("/* (non-Javadoc)\n"); result.append(" * @see org.eclipse.ui.ISizeProvider#getSizeFlags(boolean)\n"); result.append(" */\n"); result.append("public int getSizeFlags(boolean width) {\n"); result.append("\tint flags = 0;\n"); result.append("\tif (width) {\n"); if (minWidth != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.MIN;\n"); } if (maxWidth != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.MAX;\n"); } if (quantizedWidth != ISizeProvider.INFINITE || fixedArea != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.FILL;\n"); } if (fixedArea != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.WRAP;\n"); } result.append("\t} else {\n"); if (minHeight != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.MIN;\n"); } if (maxHeight != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.MAX;\n"); } if (quantizedHeight != ISizeProvider.INFINITE || fixedArea != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.FILL;\n"); } if (fixedArea != ISizeProvider.INFINITE) { result.append("\t\tflags |= SWT.WRAP;\n"); } result.append("\t}\n"); result.append("\treturn flags;\n"); result.append("}\n\n"); return result.toString(); } /** * @param minWidth2 * @return */ private int getInt(Text text) { if (text.getText().equals("")) { return ISizeProvider.INFINITE; } try { return Integer.parseInt(text.getText()); } catch (NumberFormatException e) { return ISizeProvider.INFINITE; } } /** * */ protected void updateLayout() { firePropertyChange(IWorkbenchPartConstants.PROP_PREFERRED_SIZE); } /** * @param parent */ private Text createText(Composite parent) { return new Text(parent, SWT.BORDER); } public void setFocus() { control.setFocus(); } /* (non-Javadoc) * @see org.eclipse.ui.ISizeProvider#computePreferredSize(boolean, int, int, int) */ public int computePreferredSize(boolean width, int availableParallel, int availablePerpendicular, int preferredResult) { int result = preferredResult; if (fixedArea != ISizeProvider.INFINITE) { // Try to maintain a fixed area result = (availablePerpendicular != 0) ? fixedArea / availablePerpendicular : 0; if (result < 30) result = 30; } if (width) { if (quantizedWidth != ISizeProvider.INFINITE && quantizedWidth != 0) { // Jump to the nearest multiple of the quantized size result = Math.min(result + quantizedWidth / 2, availableParallel); result = result - (result % quantizedWidth); } if (minWidth != ISizeProvider.INFINITE) { // Ensure we go no smaller than the minimum size if (result < minWidth) result = minWidth; } if (maxWidth != ISizeProvider.INFINITE) { // Ensure we go no larger than the maximum size if (result > maxWidth) result = maxWidth; } } else { // Jump to the nearest multiple of the quantized size if (quantizedHeight != ISizeProvider.INFINITE && quantizedHeight != 0) { result = Math.min(result + quantizedHeight / 2, availableParallel); result = result - (result % quantizedHeight); } if (minHeight != ISizeProvider.INFINITE) { // Ensure we go no smaller than the minimum size if (result < minHeight) result = minHeight; } if (maxHeight != ISizeProvider.INFINITE) { // Ensure we go no larger than the maximum size if (result > maxHeight) result = maxHeight; } } // Ensure that we do not use more than the available space if (result > availableParallel) result = availableParallel; if (result < 0) result = 0; return result; } private String computePreferredSizeString() { StringBuffer result = new StringBuffer(); result.append("/* (non-Javadoc)\n"); result.append(" * @see org.eclipse.ui.ISizeProvider#computePreferredSize(boolean, int, int, int)\n"); result.append(" */\n"); result.append("public int computePreferredSize(boolean width, int availableParallel,\n"); result.append("\tint availablePerpendicular, int preferredResult) {\n"); result.append("\tint result = preferredResult;\n"); if (fixedArea != ISizeProvider.INFINITE) { result.append("\t// Try to maintain a fixed area\n"); result.append( "\tresult = (availablePerpendicular != 0) ? " + fixedArea + "/availablePerpendicular : 0;\n"); result.append("\tif (result < 30) result = 30;\n"); } result.append("\tif (width) {\n"); if (quantizedWidth != ISizeProvider.INFINITE && quantizedWidth != 0) { result.append("\t\t// Jump to the nearest multiple of the quantized size\n"); result.append("\t\tresult = Math.min(result + " + quantizedWidth + "/2, availableParallel);\n"); result.append("\t\tresult = result - (result % " + quantizedWidth + ");\n"); } if (minWidth != ISizeProvider.INFINITE) { result.append("\t\t// Ensure we go no smaller than the minimum size\n"); result.append("\t\tif (result < " + minWidth + ") result = " + minWidth + ";\n"); } if (maxWidth != ISizeProvider.INFINITE) { result.append("\t\t// Ensure we go no larger than the maximum size\n"); result.append("\t\tif (result > " + maxWidth + ") result = " + maxWidth + ";\n"); } result.append("\t} else {\n"); if (quantizedHeight != ISizeProvider.INFINITE && quantizedHeight != 0) { result.append("\t\t// Jump to the nearest multiple of the quantized size\n"); result.append("\t\tresult = Math.min(result + " + quantizedHeight + "/2, availableParallel);\n"); result.append("\t\tresult = result - (result % " + quantizedHeight + ");\n"); } if (minHeight != ISizeProvider.INFINITE) { result.append("\t\t// Ensure we go no smaller than the minimum size\n"); result.append("\t\tif (result < " + minHeight + ") result = " + minHeight + ";\n"); } if (maxHeight != ISizeProvider.INFINITE) { result.append("\t\t// Ensure we go no larger than the maximum size\n"); result.append("\t\tif (result > " + maxHeight + ") result = " + maxHeight + ";\n"); } result.append("\t}\n"); result.append("\t// Ensure that we do not use more than the available space\n"); result.append("\tif (result > availableParallel) result = availableParallel;\n"); result.append("\tif (result < 0) result = 0;\n"); result.append("\treturn result;\n"); result.append("}\n"); return result.toString(); } }