Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2008 QNX Software Systems 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: * QNX Software Systems - Initial API and implementation * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.cdt.internal.ui.preferences; import java.io.File; import java.util.HashSet; import java.util.Set; import java.util.SortedMap; import java.util.TreeMap; import java.util.Map.Entry; import org.eclipse.core.resources.IPathVariableManager; import org.eclipse.core.resources.IResource; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IPath; import org.eclipse.core.runtime.Path; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.ErrorDialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.window.Window; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontMetrics; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Table; import org.eclipse.swt.widgets.TableItem; import org.eclipse.ui.ISharedImages; import org.eclipse.ui.PlatformUI; import org.eclipse.cdt.core.CCorePlugin; import org.eclipse.cdt.core.resources.IPathEntryVariableManager; import org.eclipse.cdt.internal.ui.CPluginImages; /** * @deprecated in CDT 8.0. This class appears to be never used. */ @Deprecated public class PathEntryVariablesGroup { /** * Simple data structure that holds a path variable name/value pair. */ public static class PathEntryVariableElement { public String name; public IPath path; } // sizing constants private static final int SIZING_SELECTION_PANE_WIDTH = 400; // parent shell private Shell shell; private Label variableLabel; private Table variableTable; private Button addButton; private Button editButton; private Button removeButton; // used to compute layout sizes private FontMetrics fontMetrics; // create a multi select table private boolean multiSelect; // IResource.FILE and/or IResource.FOLDER private int variableType; // External listener called when the table selection changes protected Listener selectionListener; // temporary collection for keeping currently defined variables private SortedMap<String, IPath> tempPathVariables; // set of removed variables' names private Set<String> removedVariableNames; // reference to the workspace's path variable manager private IPathEntryVariableManager pathEntryVariableManager; // file image private final Image FILE_IMG = PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJ_FILE); // folder image private final Image FOLDER_IMG = PlatformUI.getWorkbench().getSharedImages() .getImage(ISharedImages.IMG_OBJ_FOLDER); // unknown (non-existent) image. created locally, dispose locally private Image imageUnkown; /** * Creates a new PathVariablesGroup. * * @param multiSelect create a multi select tree * @param variableType the type of variables that are displayed in * the widget group. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code> * logically ORed together. */ public PathEntryVariablesGroup(boolean multiSelect, int variableType) { this.multiSelect = multiSelect; this.variableType = variableType; pathEntryVariableManager = CCorePlugin.getDefault().getPathEntryVariableManager(); removedVariableNames = new HashSet<String>(); tempPathVariables = new TreeMap<String, IPath>(); // initialize internal model initTemporaryState(); } /** * Creates a new PathVariablesGroup. * * @param multiSelect create a multi select tree * @param variableType the type of variables that are displayed in * the widget group. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code> * logically ORed together. * @param selectionListener listener notified when the selection changes * in the variables list. */ public PathEntryVariablesGroup(boolean multiSelect, int variableType, Listener selectionListener) { this(multiSelect, variableType); this.selectionListener = selectionListener; } /** * Opens a dialog for creating a new variable. */ protected void addNewVariable() { // constructs a dialog for editing the new variable's current name and value PathEntryVariableDialog dialog = new PathEntryVariableDialog(shell, PathEntryVariableDialog.NEW_VARIABLE, variableType, tempPathVariables.keySet()); // opens the dialog - just returns if the user cancels it if (dialog.open() == Window.CANCEL) return; // otherwise, adds the new variable (or updates an existing one) in the // temporary collection of currently defined variables String newVariableName = dialog.getVariableName(); IPath newVariableValue = new Path(dialog.getVariableValue()); tempPathVariables.put(newVariableName, newVariableValue); // the UI must be updated updateWidgetState(newVariableName); } /** * Creates the widget group. * Callers must call <code>dispose</code> when the group is no * longer needed. * * @param parent the widget parent * @return container of the widgets */ public Control createContents(Composite parent) { Font font = parent.getFont(); if (imageUnkown == null) { ImageDescriptor descriptor = CPluginImages.DESC_OVR_WARNING; imageUnkown = descriptor.createImage(); } initializeDialogUnits(parent); shell = parent.getShell(); // define container & its layout Composite pageComponent = new Composite(parent, SWT.NULL); GridLayout layout = new GridLayout(); layout.numColumns = 2; layout.marginWidth = 0; layout.marginHeight = 0; pageComponent.setLayout(layout); GridData data = new GridData(GridData.FILL_BOTH); data.widthHint = SIZING_SELECTION_PANE_WIDTH; pageComponent.setLayoutData(data); pageComponent.setFont(font); // layout the table & its buttons variableLabel = new Label(pageComponent, SWT.LEFT); variableLabel.setText(PreferencesMessages.PathEntryVariablesBlock_variablesLabel); data = new GridData(); data.horizontalAlignment = GridData.FILL; data.horizontalSpan = 2; variableLabel.setLayoutData(data); variableLabel.setFont(font); int tableStyle = SWT.BORDER | SWT.FULL_SELECTION; if (multiSelect) { tableStyle |= SWT.MULTI; } variableTable = new Table(pageComponent, tableStyle); variableTable.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { updateEnabledState(); if (selectionListener != null) selectionListener.handleEvent(new Event()); } }); data = new GridData(GridData.FILL_BOTH); data.heightHint = variableTable.getItemHeight() * 7; variableTable.setLayoutData(data); variableTable.setFont(font); createButtonGroup(pageComponent); // populate table with current internal state and set buttons' initial state updateWidgetState(null); return pageComponent; } /** * Disposes the group's resources. */ public void dispose() { if (imageUnkown != null) { imageUnkown.dispose(); imageUnkown = null; } } /** * Opens a dialog for editing an existing variable. * * @see PathEntryVariableDialog */ protected void editSelectedVariable() { // retrieves the name and value for the currently selected variable TableItem item = variableTable.getItem(variableTable.getSelectionIndex()); String variableName = (String) item.getData(); IPath variableValue = tempPathVariables.get(variableName); // constructs a dialog for editing the variable's current name and value PathEntryVariableDialog dialog = new PathEntryVariableDialog(shell, PathEntryVariableDialog.EXISTING_VARIABLE, variableType, tempPathVariables.keySet()); dialog.setVariableName(variableName); dialog.setVariableValue(variableValue.toOSString()); // opens the dialog - just returns if the user cancels it if (dialog.open() == Window.CANCEL) return; // the name can be changed, so we remove the current variable definition... removedVariableNames.add(variableName); tempPathVariables.remove(variableName); String newVariableName = dialog.getVariableName(); IPath newVariableValue = new Path(dialog.getVariableValue()); // and add it again (maybe with a different name) tempPathVariables.put(newVariableName, newVariableValue); // now we must refresh the UI state updateWidgetState(newVariableName); } /** * Returns the enabled state of the group's widgets. * Returns <code>true</code> if called prior to calling * <code>createContents</code>. * * @return boolean the enabled state of the group's widgets. * <code>true</code> if called prior to calling <code>createContents</code>. */ public boolean getEnabled() { if (variableTable != null && !variableTable.isDisposed()) { return variableTable.getEnabled(); } return true; } /** * Returns the selected variables. * * @return the selected variables. Returns an empty array if * the widget group has not been created yet by calling * <code>createContents</code> */ public PathEntryVariableElement[] getSelection() { if (variableTable == null) { return new PathEntryVariableElement[0]; } TableItem[] items = variableTable.getSelection(); PathEntryVariableElement[] selection = new PathEntryVariableElement[items.length]; for (int i = 0; i < items.length; i++) { String name = (String) items[i].getData(); selection[i] = new PathEntryVariableElement(); selection[i].name = name; selection[i].path = tempPathVariables.get(name); } return selection; } /** * Creates the add/edit/remove buttons * * @param parent the widget parent */ private void createButtonGroup(Composite parent) { Font font = parent.getFont(); Composite groupComponent = new Composite(parent, SWT.NULL); GridLayout groupLayout = new GridLayout(); groupLayout.marginWidth = 0; groupLayout.marginHeight = 0; groupComponent.setLayout(groupLayout); GridData data = new GridData(); data.verticalAlignment = GridData.FILL; data.horizontalAlignment = GridData.FILL; groupComponent.setLayoutData(data); groupComponent.setFont(font); addButton = new Button(groupComponent, SWT.PUSH); addButton.setText(PreferencesMessages.PathEntryVariablesBlock_addVariableButton); addButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { addNewVariable(); } }); addButton.setFont(font); setButtonLayoutData(addButton); editButton = new Button(groupComponent, SWT.PUSH); editButton.setText(PreferencesMessages.PathEntryVariablesBlock_editVariableButton); editButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { editSelectedVariable(); } }); editButton.setFont(font); setButtonLayoutData(editButton); removeButton = new Button(groupComponent, SWT.PUSH); removeButton.setText(PreferencesMessages.PathEntryVariablesBlock_removeVariableButton); removeButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { removeSelectedVariables(); } }); removeButton.setFont(font); setButtonLayoutData(removeButton); } /** * Initializes the computation of horizontal and vertical dialog units * based on the size of current font. * <p> * This method must be called before <code>setButtonLayoutData</code> * is called. * </p> * * @param control a control from which to obtain the current font */ protected void initializeDialogUnits(Control control) { // Compute and store a font metric GC gc = new GC(control); gc.setFont(control.getFont()); fontMetrics = gc.getFontMetrics(); gc.dispose(); } /** * (Re-)Initialize collections used to mantain temporary variable state. */ private void initTemporaryState() { String[] varNames = pathEntryVariableManager.getVariableNames(); tempPathVariables.clear(); for (String varName : varNames) { IPath value = pathEntryVariableManager.getValue(varName); // the value may not exist any more if (value != null) { boolean isFile = value.toFile().isFile(); if ((isFile && (variableType & IResource.FILE) != 0) || (isFile == false && (variableType & IResource.FOLDER) != 0)) { tempPathVariables.put(varName, value); } } } removedVariableNames.clear(); } /** * Updates button enabled state, depending on the number of currently selected * variables in the table. */ protected void updateEnabledState() { int itemsSelectedCount = variableTable.getSelectionCount(); editButton.setEnabled(itemsSelectedCount == 1); removeButton.setEnabled(itemsSelectedCount > 0); } /** * Rebuilds table widget state with the current list of variables (reflecting * any changes, additions and removals), and selects the item corresponding to * the given variable name. If the variable name is <code>null</code>, the * first item (if any) will be selected. * * @param selectedVarName the name for the variable to be selected (may be * <code>null</code>) * @see IPathVariableManager#getPathVariableNames() * @see IPathVariableManager#getValue(String) */ private void updateVariableTable(String selectedVarName) { variableTable.removeAll(); int selectedVarIndex = 0; for (String varName : tempPathVariables.keySet()) { TableItem item = new TableItem(variableTable, SWT.NONE); IPath value = tempPathVariables.get(varName); File file = value.toFile(); item.setText(varName + " - " + value.toOSString()); //$NON-NLS-1$ // the corresponding variable name is stored in each table widget item item.setData(varName); item.setImage(file.exists() ? (file.isFile() ? FILE_IMG : FOLDER_IMG) : imageUnkown); if (varName.equals(selectedVarName)) selectedVarIndex = variableTable.getItemCount() - 1; } if (variableTable.getItemCount() > selectedVarIndex) { variableTable.setSelection(selectedVarIndex); if (selectionListener != null) selectionListener.handleEvent(new Event()); } else if (variableTable.getItemCount() == 0 && selectionListener != null) selectionListener.handleEvent(new Event()); } /** * Commits the temporary state to the path variable manager in response to user * confirmation. * * @see IPathEntryVariableManager#setValue(String, IPath) */ public boolean performOk() { try { // first process removed variables for (String removedVariableName : removedVariableNames) { // only removes variables that have not been added again if (!tempPathVariables.containsKey(removedVariableName)) pathEntryVariableManager.setValue(removedVariableName, null); } // then process the current collection of variables, adding/updating them for (Entry<String, IPath> entry : tempPathVariables.entrySet()) { String variableName = entry.getKey(); IPath variableValue = entry.getValue(); pathEntryVariableManager.setValue(variableName, variableValue); } // re-initialize temporary state initTemporaryState(); // performOk accepted return true; } catch (CoreException ce) { ErrorDialog.openError(shell, null, null, ce.getStatus()); } return false; } /** * Removes the currently selected variables. */ protected void removeSelectedVariables() { // remove each selected element int[] selectedIndices = variableTable.getSelectionIndices(); for (int selectedIndice : selectedIndices) { TableItem selectedItem = variableTable.getItem(selectedIndice); String varName = (String) selectedItem.getData(); removedVariableNames.add(varName); tempPathVariables.remove(varName); } updateWidgetState(null); } /** * Sets the <code>GridData</code> on the specified button to * be one that is spaced for the current dialog page units. The * method <code>initializeDialogUnits</code> must be called once * before calling this method for the first time. * * @param button the button to set the <code>GridData</code> * @return the <code>GridData</code> set on the specified button */ private GridData setButtonLayoutData(Button button) { GridData data = new GridData(GridData.HORIZONTAL_ALIGN_FILL); int widthHint = Dialog.convertHorizontalDLUsToPixels(fontMetrics, IDialogConstants.BUTTON_WIDTH); data.widthHint = Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x); button.setLayoutData(data); return data; } /** * Sets the enabled state of the group's widgets. * Does nothing if called prior to calling <code>createContents</code>. * * @param enabled the new enabled state of the group's widgets */ public void setEnabled(boolean enabled) { if (variableTable != null && !variableTable.isDisposed()) { variableLabel.setEnabled(enabled); variableTable.setEnabled(enabled); addButton.setEnabled(enabled); if (enabled) updateEnabledState(); else { editButton.setEnabled(enabled); removeButton.setEnabled(enabled); } } } /** * Updates the widget's current state: refreshes the table with the current * defined variables, selects the item corresponding to the given variable * (selects the first item if <code>null</code> is provided) and updates * the enabled state for the Add/Remove/Edit buttons. * * @param selectedVarName the name of the variable to be selected (may be null) */ private void updateWidgetState(String selectedVarName) { updateVariableTable(selectedVarName); updateEnabledState(); } }