Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2005 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 descent.internal.ui.preferences.formatter; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Observable; import java.util.Observer; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Status; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.SashForm; import org.eclipse.swt.custom.ScrolledComposite; import org.eclipse.swt.events.FocusAdapter; import org.eclipse.swt.events.FocusEvent; import org.eclipse.swt.events.FocusListener; import org.eclipse.swt.events.ModifyEvent; import org.eclipse.swt.events.ModifyListener; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Text; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.IDialogSettings; import descent.internal.corext.util.Messages; import descent.ui.JavaUI; import descent.internal.ui.JavaPlugin; import descent.internal.ui.util.PixelConverter; public abstract class ModifyDialogTabPage { public interface IModificationListener { void updateStatus(IStatus status); void valuesModified(); } /** * This is the default listener for any of the Preference * classes. It is added by the respective factory methods and * updates the page's preview on each change. */ protected final Observer fUpdater = new Observer() { public void update(Observable o, Object arg) { doUpdatePreview(); notifyValuesModified(); } }; /** * The base class of all Preference classes. A preference class provides a wrapper * around one or more SWT widgets and handles the input of values for some key. * On each change, the new value is written to the map and the listeners are notified. */ protected abstract class Preference extends Observable { private final Map fPreferences; private boolean fEnabled; private String fKey; /** * Create a new Preference. * @param preferences The map where the value is written. * @param key The key for which a value is managed. */ public Preference(Map preferences, String key) { fPreferences = preferences; fEnabled = true; fKey = key; } /** * @return Gets the map of this Preference. */ protected final Map getPreferences() { return fPreferences; } /** * Set the enabled state of all SWT widgets of this preference. * @param enabled new value */ public final void setEnabled(boolean enabled) { fEnabled = enabled; updateWidget(); } /** * @return Gets the enabled state of all SWT widgets of this Preference. */ public final boolean getEnabled() { return fEnabled; } /** * Set the key which is used to store the value. * @param key New value */ public final void setKey(String key) { if (key == null || !fKey.equals(key)) { fKey = key; updateWidget(); } } /** * @return Gets the currently used key which is used to store the value. */ public final String getKey() { return fKey; } /** * Returns the main control of a preference, which is mainly used to * manage the focus. This may be <code>null</code> if the preference doesn't * have a control which is able to have the focus. * @return The main control */ public abstract Control getControl(); /** * To be implemented in subclasses. Update the SWT widgets when the state * of this object has changed (enabled, key, ...). */ protected abstract void updateWidget(); } /** * Wrapper around a checkbox and a label. */ protected class ButtonPreference extends Preference { private final String[] fValues; private final Button fCheckbox; /** * Create a new CheckboxPreference. * @param composite The composite on which the SWT widgets are added. * @param numColumns The number of columns in the composite's GridLayout. * @param preferences The map to store the values. * @param key The key to store the values. * @param values An array of two elements indicating the values to store on unchecked/checked. * @param text The label text for this Preference. * @param style SWT style flag for the button */ public ButtonPreference(Composite composite, int numColumns, Map preferences, String key, String[] values, String text, int style) { super(preferences, key); if (values == null || text == null) throw new IllegalArgumentException( FormatterMessages.ModifyDialogTabPage_error_msg_values_text_unassigned); fValues = values; fCheckbox = new Button(composite, style); fCheckbox.setText(text); fCheckbox.setLayoutData(createGridData(numColumns, GridData.FILL_HORIZONTAL, SWT.DEFAULT)); fCheckbox.setFont(composite.getFont()); updateWidget(); fCheckbox.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { checkboxChecked(((Button) e.widget).getSelection()); } }); } protected void checkboxChecked(boolean state) { getPreferences().put(getKey(), state ? fValues[1] : fValues[0]); setChanged(); notifyObservers(); } protected void updateWidget() { if (getKey() != null) { fCheckbox.setEnabled(getEnabled()); fCheckbox.setSelection(getChecked()); } else { fCheckbox.setSelection(false); fCheckbox.setEnabled(false); } } public boolean getChecked() { return fValues[1].equals(getPreferences().get(getKey())); } public void setChecked(boolean checked) { getPreferences().put(getKey(), checked ? fValues[1] : fValues[0]); updateWidget(); checkboxChecked(checked); } public Control getControl() { return fCheckbox; } } protected final class CheckboxPreference extends ButtonPreference { public CheckboxPreference(Composite composite, int numColumns, Map preferences, String key, String[] values, String text) { super(composite, numColumns, preferences, key, values, text, SWT.CHECK); } } protected final class RadioPreference extends ButtonPreference { public RadioPreference(Composite composite, int numColumns, Map preferences, String key, String[] values, String text) { super(composite, numColumns, preferences, key, values, text, SWT.RADIO); } } /** * Wrapper around a Combo box. */ protected final class ComboPreference extends Preference { private final String[] fItems; private final String[] fValues; private final Combo fCombo; /** * Create a new ComboPreference. * @param composite The composite on which the SWT widgets are added. * @param numColumns The number of columns in the composite's GridLayout. * @param preferences The map to store the values. * @param key The key to store the values. * @param values An array of n elements indicating the values to store for each selection. * @param text The label text for this Preference. * @param items An array of n elements indicating the text to be written in the combo box. */ public ComboPreference(Composite composite, int numColumns, Map preferences, String key, String[] values, String text, String[] items) { super(preferences, key); if (values == null || items == null || text == null) throw new IllegalArgumentException( FormatterMessages.ModifyDialogTabPage_error_msg_values_items_text_unassigned); fValues = values; fItems = items; createLabel(numColumns - 1, composite, text); fCombo = new Combo(composite, SWT.SINGLE | SWT.READ_ONLY); fCombo.setFont(composite.getFont()); fCombo.setItems(items); int max = 0; for (int i = 0; i < items.length; i++) if (items[i].length() > max) max = items[i].length(); fCombo.setLayoutData(createGridData(1, GridData.HORIZONTAL_ALIGN_FILL, fCombo.computeSize(SWT.DEFAULT, SWT.DEFAULT).x)); updateWidget(); fCombo.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { comboSelected(((Combo) e.widget).getSelectionIndex()); } }); } protected void comboSelected(int index) { getPreferences().put(getKey(), fValues[index]); setChanged(); notifyObservers(fValues[index]); } protected void updateWidget() { if (getKey() != null) { fCombo.setEnabled(getEnabled()); fCombo.setText(getSelectedItem()); } else { fCombo.setText(""); //$NON-NLS-1$ fCombo.setEnabled(false); } } public String getSelectedItem() { final String selected = (String) getPreferences().get(getKey()); for (int i = 0; i < fValues.length; i++) { if (fValues[i].equals(selected)) { return fItems[i]; } } return ""; //$NON-NLS-1$ } public boolean hasValue(String value) { return value.equals(getPreferences().get(getKey())); } public Control getControl() { return fCombo; } } /** * Wrapper around a textfied which requests an integer input of a given range. */ protected final class NumberPreference extends Preference { private final int fMinValue, fMaxValue; private final Label fNumberLabel; private final Text fNumberText; protected int fSelected; protected int fOldSelected; /** * Create a new NumberPreference. * @param composite The composite on which the SWT widgets are added. * @param numColumns The number of columns in the composite's GridLayout. * @param preferences The map to store the values. * @param key The key to store the values. * @param minValue The minimum value which is valid input. * @param maxValue The maximum value which is valid input. * @param text The label text for this Preference. */ public NumberPreference(Composite composite, int numColumns, Map preferences, String key, int minValue, int maxValue, String text) { super(preferences, key); fNumberLabel = createLabel(numColumns - 1, composite, text, GridData.FILL_HORIZONTAL); fNumberText = new Text(composite, SWT.SINGLE | SWT.BORDER | SWT.RIGHT); fNumberText.setFont(composite.getFont()); final int length = Integer.toString(maxValue).length() + 3; fNumberText.setLayoutData(createGridData(1, GridData.HORIZONTAL_ALIGN_END, fPixelConverter.convertWidthInCharsToPixels(length))); fMinValue = minValue; fMaxValue = maxValue; updateWidget(); fNumberText.addFocusListener(new FocusListener() { public void focusGained(FocusEvent e) { NumberPreference.this.focusGained(); } public void focusLost(FocusEvent e) { NumberPreference.this.focusLost(); } }); fNumberText.addModifyListener(new ModifyListener() { public void modifyText(ModifyEvent e) { fieldModified(); } }); } private IStatus createErrorStatus() { return new Status(IStatus.ERROR, JavaPlugin.getPluginId(), 0, Messages.format(FormatterMessages.ModifyDialogTabPage_NumberPreference_error_invalid_value, new String[] { Integer.toString(fMinValue), Integer.toString(fMaxValue) }), null); } protected void focusGained() { fOldSelected = fSelected; fNumberText.setSelection(0, fNumberText.getCharCount()); } protected void focusLost() { updateStatus(null); final String input = fNumberText.getText(); if (!validInput(input)) fSelected = fOldSelected; else fSelected = Integer.parseInt(input); if (fSelected != fOldSelected) { saveSelected(); fNumberText.setText(Integer.toString(fSelected)); } } protected void fieldModified() { final String trimInput = fNumberText.getText().trim(); final boolean valid = validInput(trimInput); updateStatus(valid ? null : createErrorStatus()); if (valid) { final int number = Integer.parseInt(trimInput); if (fSelected != number) { fSelected = number; saveSelected(); } } } private boolean validInput(String trimInput) { int number; try { number = Integer.parseInt(trimInput); } catch (NumberFormatException x) { return false; } if (number < fMinValue) return false; if (number > fMaxValue) return false; return true; } private void saveSelected() { getPreferences().put(getKey(), Integer.toString(fSelected)); setChanged(); notifyObservers(); } protected void updateWidget() { final boolean hasKey = getKey() != null; fNumberLabel.setEnabled(hasKey && getEnabled()); fNumberText.setEnabled(hasKey && getEnabled()); if (hasKey) { String s = (String) getPreferences().get(getKey()); try { fSelected = Integer.parseInt(s); } catch (NumberFormatException e) { final String message = Messages.format( FormatterMessages.ModifyDialogTabPage_NumberPreference_error_invalid_key, getKey()); JavaPlugin.log(new Status(IStatus.ERROR, JavaPlugin.getPluginId(), IStatus.OK, message, e)); s = ""; //$NON-NLS-1$ } fNumberText.setText(s); } else { fNumberText.setText(""); //$NON-NLS-1$ } } public Control getControl() { return fNumberText; } } /** * This class provides the default way to preserve and re-establish the focus * over multiple modify sessions. Each ModifyDialogTabPage has its own instance, * and it should add all relevant controls upon creation, always in the same sequence. * This established a mapping of controls to indexes, which allows to restore the focus * in a later session. * The index is saved in the dialog settings, and there is only one common preference for * all tab pages. It is always the currently active tab page which stores its focus * index. */ protected final static class DefaultFocusManager extends FocusAdapter { private final static String PREF_LAST_FOCUS_INDEX = JavaUI.ID_PLUGIN + "formatter_page.modify_dialog_tab_page.last_focus_index"; //$NON-NLS-1$ private final IDialogSettings fDialogSettings; private final Map fItemMap; private final List fItemList; private int fIndex; public DefaultFocusManager() { fDialogSettings = JavaPlugin.getDefault().getDialogSettings(); fItemMap = new HashMap(); fItemList = new ArrayList(); fIndex = 0; } public void focusGained(FocusEvent e) { fDialogSettings.put(PREF_LAST_FOCUS_INDEX, ((Integer) fItemMap.get(e.widget)).intValue()); } public void add(Control control) { control.addFocusListener(this); fItemList.add(fIndex, control); fItemMap.put(control, new Integer(fIndex++)); } public void add(Preference preference) { final Control control = preference.getControl(); if (control != null) add(control); } public boolean isUsed() { return fIndex != 0; } public void restoreFocus() { int index = 0; try { index = fDialogSettings.getInt(PREF_LAST_FOCUS_INDEX); // make sure the value is within the range if ((index >= 0) && (index <= fItemList.size() - 1)) { ((Control) fItemList.get(index)).setFocus(); } } catch (NumberFormatException ex) { // this is the first time } } public void resetFocus() { fDialogSettings.put(PREF_LAST_FOCUS_INDEX, -1); } } /** * The default focus manager. This widget knows all widgets which can have the focus * and listens for focusGained events, on which it stores the index of the current * focus holder. When the dialog is restarted, <code>restoreFocus()</code> sets the * focus to the last control which had it. * * The standard Preference object are managed by this focus manager if they are created * using the respective factory methods. Other SWT widgets can be added in subclasses * when they are created. */ protected final DefaultFocusManager fDefaultFocusManager; /** * A pixel converter for layout calculations */ protected PixelConverter fPixelConverter; /** * The map where the current settings are stored. */ protected final Map fWorkingValues; /** * The modify dialog where we can display status messages. */ private final IModificationListener fModifyListener; /* * Create a new <code>ModifyDialogTabPage</code> */ public ModifyDialogTabPage(IModificationListener modifyListener, Map workingValues) { fWorkingValues = workingValues; fModifyListener = modifyListener; fDefaultFocusManager = new DefaultFocusManager(); } /** * Create the contents of this tab page. Subclasses cannot override this, * instead they must implement <code>doCreatePreferences</code>. <code>doCreatePreview</code> may also * be overridden as necessary. * @param parent The parent composite * @return Created content control */ public final Composite createContents(Composite parent) { final int numColumns = 4; if (fPixelConverter == null) { fPixelConverter = new PixelConverter(parent); } final SashForm fSashForm = new SashForm(parent, SWT.HORIZONTAL); fSashForm.setFont(parent.getFont()); final ScrolledComposite scrollPane = new ScrolledComposite(fSashForm, SWT.V_SCROLL); scrollPane.setExpandHorizontal(true); scrollPane.setExpandVertical(true); final Composite settingsPane = new Composite(scrollPane, SWT.NONE); settingsPane.setFont(fSashForm.getFont()); scrollPane.setContent(settingsPane); final GridLayout layout = new GridLayout(numColumns, false); layout.verticalSpacing = (int) (1.5 * fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING)); layout.horizontalSpacing = fPixelConverter .convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); layout.marginHeight = fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); layout.marginWidth = fPixelConverter.convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); settingsPane.setLayout(layout); doCreatePreferences(settingsPane, numColumns); scrollPane.setMinSize(settingsPane.computeSize(SWT.DEFAULT, SWT.DEFAULT)); final Composite previewPane = new Composite(fSashForm, SWT.NONE); previewPane.setLayout(createGridLayout(numColumns, true)); previewPane.setFont(fSashForm.getFont()); doCreatePreviewPane(previewPane, numColumns); initializePage(); fSashForm.setWeights(new int[] { 3, 3 }); return fSashForm; } /** * This method is called after all controls have been alloated, including the preview. * It can be used to set the preview text and to create listeners. * */ protected abstract void initializePage(); /** * Create the left side of the modify dialog. This is meant to be implemented by subclasses. * @param composite Composite to create in * @param numColumns Number of columns to use */ protected abstract void doCreatePreferences(Composite composite, int numColumns); /** * Create the right side of the modify dialog. By default, the preview is displayed there. * Subclasses can override this method in order to customize the right-hand side of the * dialog. * @param composite Composite to create in * @param numColumns Number of columns to use * @return Created composite */ protected Composite doCreatePreviewPane(Composite composite, int numColumns) { createLabel(numColumns, composite, FormatterMessages.ModifyDialogTabPage_preview_label_text); final JavaPreview preview = doCreateJavaPreview(composite); fDefaultFocusManager.add(preview.getControl()); final GridData gd = createGridData(numColumns, GridData.FILL_BOTH, 0); gd.widthHint = 0; gd.heightHint = 0; preview.getControl().setLayoutData(gd); return composite; } /** * To be implemented by subclasses. This method should return an instance of JavaPreview. * Currently, the choice is between CompilationUnitPreview which contains a valid compilation * unit, or a SnippetPreview which formats several independent code snippets and displays them * in the same window. * @param parent Parent composite * @return Created preview */ protected abstract JavaPreview doCreateJavaPreview(Composite parent); /** * This is called when the page becomes visible. * Common tasks to do include: * <ul><li>Updating the preview.</li> * <li>Setting the focus</li> * </ul> */ final public void makeVisible() { fDefaultFocusManager.resetFocus(); doUpdatePreview(); } /** * Update the preview. To be implemented by subclasses. */ protected abstract void doUpdatePreview(); protected void notifyValuesModified() { fModifyListener.valuesModified(); } /** * Each tab page should remember where its last focus was, and reset it * correctly within this method. This method is only called after * initialization on the first tab page to be displayed in order to restore * the focus of the last session. */ public void setInitialFocus() { if (fDefaultFocusManager.isUsed()) { fDefaultFocusManager.restoreFocus(); } } /** * Set the status field on the dialog. This can be used by tab pages to report * inconsistent input. The OK button is disabled if the kind is IStatus.ERROR. * @param status Status describing the current page error state */ protected void updateStatus(IStatus status) { fModifyListener.updateStatus(status); } /* * Factory methods to make GUI construction easier */ /* * Create a GridLayout with the default margin and spacing settings, as * well as the specified number of columns. */ protected GridLayout createGridLayout(int numColumns, boolean margins) { final GridLayout layout = new GridLayout(numColumns, false); layout.verticalSpacing = fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); layout.horizontalSpacing = fPixelConverter .convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); if (margins) { layout.marginHeight = fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); layout.marginWidth = fPixelConverter.convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); } else { layout.marginHeight = 0; layout.marginWidth = 0; } return layout; } /* * Convenience method to create a GridData. */ protected static GridData createGridData(int numColumns, int style, int widthHint) { final GridData gd = new GridData(style); gd.horizontalSpan = numColumns; gd.widthHint = widthHint; return gd; } /* * Convenience method to create a label. */ protected static Label createLabel(int numColumns, Composite parent, String text) { return createLabel(numColumns, parent, text, GridData.FILL_HORIZONTAL); } /* * Convenience method to create a label */ protected static Label createLabel(int numColumns, Composite parent, String text, int gridDataStyle) { final Label label = new Label(parent, SWT.WRAP); label.setFont(parent.getFont()); label.setText(text); label.setLayoutData(createGridData(numColumns, gridDataStyle, SWT.DEFAULT)); return label; } /* * Convenience method to create a group */ protected Group createGroup(int numColumns, Composite parent, String text) { final Group group = new Group(parent, SWT.NONE); group.setFont(parent.getFont()); group.setLayoutData(createGridData(numColumns, GridData.FILL_HORIZONTAL, SWT.DEFAULT)); final GridLayout layout = new GridLayout(numColumns, false); layout.verticalSpacing = fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); layout.horizontalSpacing = fPixelConverter .convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); layout.marginHeight = fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); //layout.marginHeight= fPixelConverter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); //layout.marginWidth= fPixelConverter.convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); group.setLayout(layout);//createGridLayout(numColumns, true)); group.setText(text); return group; } /* * Convenience method to create a NumberPreference. The widget is registered as * a potential focus holder, and the default updater is added. */ protected NumberPreference createNumberPref(Composite composite, int numColumns, String name, String key, int minValue, int maxValue) { final NumberPreference pref = new NumberPreference(composite, numColumns, fWorkingValues, key, minValue, maxValue, name); fDefaultFocusManager.add(pref); pref.addObserver(fUpdater); return pref; } /* * Convenience method to create a ComboPreference. The widget is registered as * a potential focus holder, and the default updater is added. */ protected ComboPreference createComboPref(Composite composite, int numColumns, String name, String key, String[] values, String[] items) { final ComboPreference pref = new ComboPreference(composite, numColumns, fWorkingValues, key, values, name, items); fDefaultFocusManager.add(pref); pref.addObserver(fUpdater); return pref; } /* * Convenience method to create a CheckboxPreference. The widget is registered as * a potential focus holder, and the default updater is added. */ protected CheckboxPreference createCheckboxPref(Composite composite, int numColumns, String name, String key, String[] values) { final CheckboxPreference pref = new CheckboxPreference(composite, numColumns, fWorkingValues, key, values, name); fDefaultFocusManager.add(pref); pref.addObserver(fUpdater); return pref; } protected RadioPreference createRadioPref(Composite composite, int numColumns, String name, String key, String[] values) { final RadioPreference pref = new RadioPreference(composite, numColumns, fWorkingValues, key, values, name); fDefaultFocusManager.add(pref); pref.addObserver(fUpdater); return pref; } /* * Create a nice javadoc comment for some string. */ protected static String createPreviewHeader(String title) { return "/**\n* " + title + "\n*/\n"; //$NON-NLS-1$ //$NON-NLS-2$ } protected SetAllGroup createSetAllGroup(int numColumns, Composite parent, String titleText) { return new SetAllGroup(numColumns, parent, titleText); } protected SetAllOption createSetAllOption(SetAllGroup parent, String option, String text) { return new SetAllOption(parent, option, text); } protected final class SetAllGroup { protected final Group group; protected final List<Preference> preferences = new ArrayList<Preference>(); private SetAllGroup(int numColumns, Composite parent, String titleText) { group = createGroup(numColumns, parent, titleText); } protected void addPreference(Preference pref) { preferences.add(pref); } protected void addPreferences(Preference[] prefs) { for (Preference pref : prefs) addPreference(pref); } protected void notify(String option) { for (Preference pref : preferences) { if (pref instanceof ComboPreference) { ComboPreference cpref = (ComboPreference) pref; Combo ctrl = (Combo) cpref.getControl(); int index = ctrl.indexOf(option, 0); ctrl.select(index); cpref.comboSelected(index); } } } } protected static final class SetAllOption implements SelectionListener { private final String option; private final SetAllGroup parent; private final Button button; private SetAllOption(SetAllGroup $parent, String $option, String text) { option = $option; parent = $parent; button = new Button(parent.group, SWT.PUSH); button.setFont(parent.group.getFont()); button.setText(text); button.addSelectionListener(this); } public String getOption() { return option; } public void widgetDefaultSelected(SelectionEvent e) { // Shouldn't be called } public void widgetSelected(SelectionEvent e) { parent.notify(option); } } }