Java tutorial
/* * Copyright (c) 2004-2006 Marco Maccaferri 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: * Marco Maccaferri - initial API and implementation */ package net.sourceforge.eclipsetrader.core.ui; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.DialogPage; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.preference.IPreferencePage; import org.eclipse.jface.preference.IPreferencePageContainer; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import org.eclipse.jface.wizard.IWizard; import org.eclipse.jface.wizard.IWizardContainer; import org.eclipse.jface.wizard.IWizardPage; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.Point; 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.Shell; public abstract class PluginPreferencePage extends DialogPage implements IWizardPage, IPreferencePage { /** * Preference store, or <code>null</code>. */ private IPreferenceStore preferenceStore; /** * Valid state for this page; <code>true</code> by default. * * @see #isValid */ private boolean isValid = true; /** * Body of page. */ private Control body; /** * Whether this page has the standard Apply and Defaults buttons; * <code>true</code> by default. * * @see #noDefaultAndApplyButton */ private boolean createDefaultAndApplyButton = true; /** * Standard Defaults button, or <code>null</code> if none. * This button has id <code>DEFAULTS_ID</code>. */ private Button defaultsButton = null; /** * The container this preference page belongs to; <code>null</code> * if none. */ private IPreferencePageContainer container = null; /** * Standard Apply button, or <code>null</code> if none. * This button has id <code>APPLY_ID</code>. */ private Button applyButton = null; /** * Description label. * * @see #createDescriptionLabel(Composite) */ private Label descriptionLabel; /** * Caches size of page. */ private Point size = null; /** * The wizard to which this page belongs; <code>null</code> * if this page has yet to be added to a wizard. */ private IWizard wizard = null; /** * The page that was shown right before this page became visible; * <code>null</code> if none. */ private IWizardPage previousPage = null; /** * Creates a new preference page with an empty title and no image. */ protected PluginPreferencePage() { this(""); //$NON-NLS-1$ } /** * Creates a new preference page with the given title and no image. * * @param title the title of this preference page */ protected PluginPreferencePage(String title) { super(title); } /** * Creates a new abstract preference page with the given title and image. * * @param title the title of this preference page * @param image the image for this preference page, * or <code>null</code> if none */ protected PluginPreferencePage(String title, ImageDescriptor image) { super(title, image); } /** * Computes the size for this page's UI control. * <p> * The default implementation of this <code>IPreferencePage</code> * method returns the size set by <code>setSize</code>; if no size * has been set, but the page has a UI control, the framework * method <code>doComputeSize</code> is called to compute the size. * </p> * * @return the size of the preference page encoded as * <code>new Point(width,height)</code>, or * <code>(0,0)</code> if the page doesn't currently have any UI component */ public Point computeSize() { if (size != null) return size; Control control = getControl(); if (control != null) { size = doComputeSize(); return size; } return new Point(0, 0); } /** * Contributes additional buttons to the given composite. * <p> * The default implementation of this framework hook method does * nothing. Subclasses should override this method to contribute buttons * to this page's button bar. For each button a subclass contributes, * it must also increase the parent's grid layout number of columns * by one; that is, * <pre> * ((GridLayout) parent.getLayout()).numColumns++); * </pre> * </p> * * @param parent the button bar */ protected void contributeButtons(Composite parent) { } /** * Creates and returns the SWT control for the customized body * of this preference page under the given parent composite. * <p> * This framework method must be implemented by concrete subclasses. Any * subclass returning a <code>Composite</code> object whose <code>Layout</code> * has default margins (for example, a <code>GridLayout</code>) are expected to * set the margins of this <code>Layout</code> to 0 pixels. * </p> * * @param parent the parent composite * @return the new control */ protected abstract Control createContents(Composite parent); /** * The <code>PreferencePage</code> implementation of this * <code>IDialogPage</code> method creates a description label * and button bar for the page. It calls <code>createContents</code> * to create the custom contents of the page. * <p> * If a subclass that overrides this method creates a <code>Composite</code> * that has a layout with default margins (for example, a <code>GridLayout</code>) * it is expected to set the margins of this <code>Layout</code> to 0 pixels. */ public void createControl(Composite parent) { GridData gd; Composite content = new Composite(parent, SWT.NONE); setControl(content); GridLayout layout = new GridLayout(); layout.marginWidth = 0; layout.marginHeight = 0; content.setLayout(layout); //Apply the font on creation for backward compatibility applyDialogFont(content); // initialize the dialog units initializeDialogUnits(content); descriptionLabel = createDescriptionLabel(content); if (descriptionLabel != null) { descriptionLabel.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); } body = createContents(content); if (body != null) // null is not a valid return value but support graceful failure body.setLayoutData(new GridData(GridData.FILL_BOTH)); Composite buttonBar = new Composite(content, SWT.NONE); layout = new GridLayout(); layout.numColumns = 0; layout.marginHeight = 0; layout.marginWidth = 0; layout.makeColumnsEqualWidth = false; buttonBar.setLayout(layout); gd = new GridData(GridData.HORIZONTAL_ALIGN_END); buttonBar.setLayoutData(gd); contributeButtons(buttonBar); if (createDefaultAndApplyButton) { layout.numColumns = layout.numColumns + 2; String[] labels = JFaceResources.getStrings(new String[] { "defaults", "apply" }); //$NON-NLS-2$//$NON-NLS-1$ int widthHint = convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH); defaultsButton = new Button(buttonBar, SWT.PUSH); defaultsButton.setText(labels[0]); Dialog.applyDialogFont(defaultsButton); GridData data = new GridData(GridData.HORIZONTAL_ALIGN_FILL); Point minButtonSize = defaultsButton.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); data.widthHint = Math.max(widthHint, minButtonSize.x); defaultsButton.setLayoutData(data); defaultsButton.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { performDefaults(); } }); applyButton = new Button(buttonBar, SWT.PUSH); applyButton.setText(labels[1]); Dialog.applyDialogFont(applyButton); data = new GridData(GridData.HORIZONTAL_ALIGN_FILL); minButtonSize = applyButton.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); data.widthHint = Math.max(widthHint, minButtonSize.x); applyButton.setLayoutData(data); applyButton.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { performApply(); } }); applyButton.setEnabled(isValid()); applyDialogFont(buttonBar); } else { /* Check if there are any other buttons on the button bar. * If not, throw away the button bar composite. Otherwise * there is an unusually large button bar. */ if (buttonBar.getChildren().length < 1) buttonBar.dispose(); } } /** * Apply the dialog font to the composite and it's children * if it is set. Subclasses may override if they wish to * set the font themselves. * @param composite */ protected void applyDialogFont(Composite composite) { Dialog.applyDialogFont(composite); } /** * Creates and returns an SWT label under the given composite. * * @param parent the parent composite * @return the new label */ protected Label createDescriptionLabel(Composite parent) { Label result = null; String description = getDescription(); if (description != null) { result = new Label(parent, SWT.WRAP); result.setFont(parent.getFont()); result.setText(description); } return result; } /** * Computes the size needed by this page's UI control. * <p> * All pages should override this method and set the appropriate sizes * of their widgets, and then call <code>super.doComputeSize</code>. * </p> * * @return the size of the preference page encoded as * <code>new Point(width,height)</code> */ protected Point doComputeSize() { if (descriptionLabel != null && body != null) { Point bodySize = body.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); GridData gd = (GridData) descriptionLabel.getLayoutData(); gd.widthHint = bodySize.x; } return getControl().computeSize(SWT.DEFAULT, SWT.DEFAULT, true); } /** * Returns the preference store of this preference page. * <p> * This is a framework hook method for subclasses to return a * page-specific preference store. The default implementation * returns <code>null</code>. * </p> * * @return the preference store, or <code>null</code> if none */ protected IPreferenceStore doGetPreferenceStore() { return null; } /** * Returns the container of this page. * * @return the preference page container, or <code>null</code> if this * page has yet to be added to a container */ public Object getContainer() { return container; } /** * Returns the preference store of this preference page. * * @return the preference store , or <code>null</code> if none */ public IPreferenceStore getPreferenceStore() { if (preferenceStore == null) preferenceStore = doGetPreferenceStore(); if (preferenceStore != null) return preferenceStore; else if (container != null) return container.getPreferenceStore(); return null; } /** * The preference page implementation of an <code>IPreferencePage</code> * method returns whether this preference page is valid. Preference * pages are considered valid by default; call <code>setValid(false)</code> * to make a page invalid. */ public boolean isValid() { return isValid; } /** * Suppresses creation of the standard Default and Apply buttons * for this page. * <p> * Subclasses wishing a preference page wihthout these buttons * should call this framework method before the page's control * has been created. * </p> */ protected void noDefaultAndApplyButton() { createDefaultAndApplyButton = false; } /** * The <code>PreferencePage</code> implementation of this * <code>IPreferencePage</code> method returns <code>true</code> * if the page is valid. */ public boolean okToLeave() { return isValid(); } /** * Performs special processing when this page's Apply button has been pressed. * <p> * This is a framework hook method for sublcasses to do special things when * the Apply button has been pressed. * The default implementation of this framework method simply calls * <code>performOk</code> to simulate the pressing of the page's OK button. * </p> * * @see #performOk */ protected void performApply() { performOk(); } /** * The preference page implementation of an <code>IPreferencePage</code> * method performs special processing when this page's Cancel button has * been pressed. * <p> * This is a framework hook method for sublcasses to do special things when * the Cancel button has been pressed. The default implementation of this * framework method does nothing and returns <code>true</code>. */ public boolean performCancel() { return true; } /** * Performs special processing when this page's Defaults button has been pressed. * <p> * This is a framework hook method for subclasses to do special things when * the Defaults button has been pressed. * Subclasses may override, but should call <code>super.performDefaults</code>. * </p> */ protected void performDefaults() { updateApplyButton(); } /** * Method declared on IPreferencePage. * Subclasses should override */ public boolean performOk() { return true; } /** (non-Javadoc) * Method declared on IPreferencePage. */ public void setContainer(IPreferencePageContainer container) { this.container = container; } /** * Sets the preference store for this preference page. * <p> * If preferenceStore is set to null, getPreferenceStore * will invoke doGetPreferenceStore the next time it is called. * </p> * * @param store the preference store, or <code>null</code> * @see #getPreferenceStore */ public void setPreferenceStore(IPreferenceStore store) { preferenceStore = store; } /* (non-Javadoc) * Method declared on IPreferencePage. */ public void setSize(Point uiSize) { Control control = getControl(); if (control != null) { control.setSize(uiSize); size = uiSize; } } /** * The <code>PreferencePage</code> implementation of this <code>IDialogPage</code> * method extends the <code>DialogPage</code> implementation to update * the preference page container title. Subclasses may extend. */ public void setTitle(String title) { super.setTitle(title); if (getContainer() instanceof IPreferencePageContainer) ((IPreferencePageContainer) getContainer()).updateTitle(); } /** * Sets whether this page is valid. * The enable state of the container buttons and the * apply button is updated when a page's valid state * changes. * <p> * * @param b the new valid state */ public void setValid(boolean b) { boolean oldValue = isValid; isValid = b; if (oldValue != isValid) { // update container state if (getContainer() instanceof IPreferencePageContainer) { ((IPreferencePageContainer) getContainer()).updateButtons(); // update page state updateApplyButton(); } if (getContainer() instanceof IWizardContainer && isCurrentPage()) ((IWizardContainer) getContainer()).updateButtons(); } } /** * Updates the enabled state of the Apply button to reflect whether * this page is valid. */ protected void updateApplyButton() { if (applyButton != null) applyButton.setEnabled(isValid()); } /** * Creates a composite with a highlighted Note entry and a message text. * This is designed to take up the full width of the page. * * @param font the font to use * @param composite the parent composite * @param title the title of the note * @param message the message for the note * @return the composite for the note */ protected Composite createNoteComposite(Font font, Composite composite, String title, String message) { Composite messageComposite = new Composite(composite, SWT.NONE); GridLayout messageLayout = new GridLayout(); messageLayout.numColumns = 2; messageLayout.marginWidth = 0; messageLayout.marginHeight = 0; messageComposite.setLayout(messageLayout); messageComposite.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL)); messageComposite.setFont(font); final Label noteLabel = new Label(messageComposite, SWT.BOLD); noteLabel.setText(title); noteLabel.setFont(JFaceResources.getBannerFont()); noteLabel.setLayoutData(new GridData(GridData.VERTICAL_ALIGN_BEGINNING)); final IPropertyChangeListener fontListener = new IPropertyChangeListener() { public void propertyChange(PropertyChangeEvent event) { if (JFaceResources.BANNER_FONT.equals(event.getProperty())) { noteLabel.setFont(JFaceResources.getFont(JFaceResources.BANNER_FONT)); } } }; JFaceResources.getFontRegistry().addListener(fontListener); noteLabel.addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent event) { JFaceResources.getFontRegistry().removeListener(fontListener); } }); Label messageLabel = new Label(messageComposite, SWT.WRAP); messageLabel.setText(message); messageLabel.setFont(font); return messageComposite; } /** * Returns the Apply button. * * @return the Apply button */ protected Button getApplyButton() { return applyButton; } /** * Returns the Restore Defaults button. * * @return the Restore Defaults button */ protected Button getDefaultsButton() { return defaultsButton; } /* (non-Javadoc) * @see org.eclipse.jface.dialogs.IDialogPage#performHelp() */ public void performHelp() { getControl().notifyListeners(SWT.Help, new Event()); } /** * Apply the data to the receiver. By default do nothing. * @param data * @since 3.1 */ public void applyData(Object data) { } /** * Returns whether this page is the current one in the wizard's container. * * @return <code>true</code> if the page is active, * and <code>false</code> otherwise */ protected boolean isCurrentPage() { return (getContainer() instanceof IWizardContainer && this == ((IWizardContainer) getContainer()).getCurrentPage()); } /** * The <code>WizardPage</code> implementation of this method * declared on <code>DialogPage</code> updates the container * if this is the current page. */ public void setErrorMessage(String newMessage) { super.setErrorMessage(newMessage); if (getContainer() instanceof IPreferencePageContainer) ((IPreferencePageContainer) getContainer()).updateMessage(); else if (getContainer() instanceof IWizardContainer && isCurrentPage()) { ((IWizardContainer) getContainer()).updateMessage(); } } /* (non-Javadoc) * @see org.eclipse.jface.dialogs.DialogPage#setMessage(java.lang.String, int) */ public void setMessage(String newMessage, int newType) { super.setMessage(newMessage, newType); if (getContainer() instanceof IPreferencePageContainer) ((IPreferencePageContainer) getContainer()).updateMessage(); else if (getContainer() instanceof IWizardContainer) ((IWizardContainer) getContainer()).updateMessage(); } /** * The <code>WizardPage</code> implementation of this <code>IWizardPage</code> * method returns <code>true</code> if this page is complete (<code>isPageComplete</code>) * and there is a next page to flip to. Subclasses may override (extend or reimplement). * * @see #getNextPage * @see #isPageComplete */ public boolean canFlipToNextPage() { return isPageComplete() && getNextPage() != null; } /* (non-Javadoc) * @see org.eclipse.jface.wizard.IWizardPage#getName() */ public String getName() { return null; } /* (non-Javadoc) * Method declared on IWizardPage. * The default behavior is to ask the wizard for the next page. */ public IWizardPage getNextPage() { if (wizard == null) return null; return wizard.getNextPage(this); } /* (non-Javadoc) * Method declared on IWizardPage. * The default behavior is return the cached previous back or, * lacking that, to ask the wizard for the previous page. */ public IWizardPage getPreviousPage() { if (previousPage != null) return previousPage; if (wizard == null) return null; return wizard.getPreviousPage(this); } /** * The <code>WizardPage</code> implementation of this method declared on * <code>DialogPage</code> returns the shell of the container. * The advantage of this implementation is that the shell is accessable * once the container is created even though this page's control may not * yet be created. */ public Shell getShell() { if (getContainer() instanceof IWizardContainer) return ((IWizardContainer) getContainer()).getShell(); if (body != null) return body.getShell(); return null; } /* (non-Javadoc) * @see org.eclipse.jface.wizard.IWizardPage#getWizard() */ public IWizard getWizard() { return wizard; } /* (non-Javadoc) * @see org.eclipse.jface.wizard.IWizardPage#isPageComplete() */ public boolean isPageComplete() { return isValid; } /* (non-Javadoc) * Method declared on IWizardPage. */ public void setPreviousPage(IWizardPage page) { previousPage = page; } /* (non-Javadoc) * Method declared on IWizardPage. */ public void setWizard(IWizard newWizard) { wizard = newWizard; } /** * Returns a string suitable for debugging purpose only. */ public String toString() { return getTitle(); } }