Provide reusable breadcrumb viewer implementations in JFace #4495

bundles/org.eclipse.jface/src/org/eclipse/jface/messages.properties

@@ -198,6 +198,11 @@ F20 = F20
 SafeRunnable.errorMessage = An error has occurred. See error log for more details.
 ColorSelector.Name=Color Selector
 
+#############################################################
+# org.eclipse.jface.viewers
+#############################################################
+BreadcrumbItemDropDown_showDropDownMenu_action_toolTip=Show Children
+
 #############################################################
 # org.eclipse.jface.viewers.deferred 
 #############################################################

bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/BreadcrumbItem.java

@@ -0,0 +1,315 @@
+/*******************************************************************************
+ * Copyright (c) 2008, 2011 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *     Fabio Zadrozny - Bug 465666
+ *******************************************************************************/
+package org.eclipse.jface.viewers;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.Font;
+import org.eclipse.swt.graphics.Image;
+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.Item;
+import org.eclipse.swt.widgets.Shell;
+
+/**
+ * An item in a breadcrumb viewer.
+ * <p>
+ * The item shows a label and an image. It also has the ability to expand, that
+ * is to open a drop down menu.
+ * </p>
+ * <p>
+ * The drop down allows to select any child of the items input element. The item
+ * shows the label and icon of its data element, if any.
+ * </p>
+ *
+ * @since 3.41
+ */
+class BreadcrumbItem extends Item {
+
+	private final BreadcrumbViewer fParent;
+	private Composite fContainer;
+
+	private BreadcrumbItemDetails fDetailsBlock;
+	private BreadcrumbItemDropDown fExpandBlock;
+	private boolean fIsLast;
+
+	/**
+	 * A new breadcrumb item which is shown inside the given viewer.
+	 *
+	 * @param viewer the items viewer
+	 * @param parent the container containing the item
+	 */
+	public BreadcrumbItem(BreadcrumbViewer viewer, Composite parent) {
+		super(parent, SWT.NONE);
+
+		fParent = viewer;
+
+		fContainer = new Composite(parent, SWT.NONE);
+		fContainer.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false));
+		GridLayout layout = new GridLayout(2, false);
+		layout.marginBottom = 1;
+		layout.marginHeight = 0;
+		layout.marginWidth = 0;
+		layout.horizontalSpacing = 0;
+		fContainer.setLayout(layout);
+
+		fDetailsBlock = new BreadcrumbItemDetails(this, fContainer);
+
+		fExpandBlock = new BreadcrumbItemDropDown(this, fContainer);
+
+		fContainer.setData("org.eclipse.e4.ui.css.id", "BreadcrumbItemComposite"); //$NON-NLS-1$ //$NON-NLS-2$
+	}
+
+	/**
+	 * Returns this items viewer.
+	 *
+	 * @return the viewer showing this item
+	 */
+	public BreadcrumbViewer getViewer() {
+		return fParent;
+	}
+
+	/*
+	 * @see org.eclipse.swt.widgets.Widget#dispose()
+	 */
+	@Override
+	public void dispose() {
+		Shell shell = fExpandBlock.getDropDownShell();
+		if (shell != null && !shell.isDisposed()) {
+			shell.dispose();
+		}
+		fContainer.dispose();
+		super.dispose();
+	}
+
+	/**
+	 * Should this item show a text label.
+	 *
+	 * @param enabled true if it should
+	 */
+	void setShowText(boolean enabled) {
+		fDetailsBlock.setTextVisible(enabled);
+	}
+
+	/**
+	 * Does this item show a text label?
+	 *
+	 * @return true if it does.
+	 */
+	boolean isShowText() {
+		return fDetailsBlock.isTextVisible();
+	}
+
+	/**
+	 * Returns the width of this item.
+	 *
+	 * @return the width of this item
+	 */
+	int getWidth() {
+		return fDetailsBlock.getWidth() + fExpandBlock.getWidth() + 2;
+	}
+
+	/**
+	 * Sets whether this item has to be marked as selected or not.
+	 *
+	 * @param selected true if marked as selected
+	 */
+	void setSelected(boolean selected) {
+		fDetailsBlock.setSelected(selected);
+	}
+
+	/**
+	 * Sets whether this item has the keyboard focus.
+	 *
+	 * @param state <code>true</code> if it has focus, <code>false</code> otherwise
+	 */
+	void setFocus(boolean state) {
+		fDetailsBlock.setFocus(state);
+	}
+
+	/**
+	 * Returns whether this item has the keyboard focus.
+	 *
+	 * @return <code>true</code> if this item has the keyboard focus
+	 */
+	boolean hasFocus() {
+		return fDetailsBlock.hasFocus();
+	}
+
+	/**
+	 * Redraws this item using the viewer's current providers.
+	 */
+	void refresh() {
+		IBaseLabelProvider labelProvider = fParent.getLabelProvider();
+
+		if (labelProvider instanceof CellLabelProvider cellLabelProvider) {
+			BreadcrumbViewerRow row = new BreadcrumbViewerRow(fParent, this);
+			ViewerCell cell = row.getCell(0);
+			cellLabelProvider.update(cell);
+		} else {
+			ILabelProvider simpleLabelProvider = (ILabelProvider) labelProvider;
+			String text = simpleLabelProvider.getText(getData());
+			Image image = simpleLabelProvider.getImage(getData());
+
+			setText(text);
+			setImage(image);
+		}
+
+		refreshToolTip();
+		refreshArrow();
+	}
+
+	void refreshToolTip() {
+		ILabelProvider toolTipLabelProvider = fParent.getToolTipLabelProvider();
+		if (toolTipLabelProvider != null) {
+			fDetailsBlock.setToolTip(toolTipLabelProvider.getText(getData()));
+		} else {
+			fDetailsBlock.setToolTip(getText());
+		}
+	}
+
+	/**
+	 * Refresh the arrows visibility.
+	 */
+	void refreshArrow() {
+		ITreeContentProvider contentProvider = (ITreeContentProvider) fParent.getContentProvider();
+		fExpandBlock.setEnabled(contentProvider.hasChildren(getData()));
+	}
+
+	/**
+	 * Set whether this is the last item in the breadcrumb item chain or not.
+	 *
+	 * @param isLast <code>true</code> if this is the last item, <code>false</code>
+	 *               otherwise
+	 */
+	void setIsLastItem(boolean isLast) {
+		fIsLast = isLast;
+
+		GridData data = (GridData) fContainer.getLayoutData();
+		data.grabExcessHorizontalSpace = isLast;
+	}
+
+	/**
+	 * Sets whether or not the this item should show the details (name and label).
+	 *
+	 * @param visible true if the item shows details
+	 */
+	void setDetailsVisible(boolean visible) {
+		fDetailsBlock.setVisible(visible);
+	}
+
+	/**
+	 * Expand this item, shows the drop down menu.
+	 */
+	void openDropDownMenu() {
+		fExpandBlock.showMenu();
+	}
+
+	/**
+	 * @return true if this item is expanded
+	 */
+	boolean isMenuShown() {
+		return fExpandBlock.isMenuShown();
+	}
+
+	/**
+	 * Returns the drop down shell.
+	 *
+	 * @return the shell of the drop down if shown, <code>null</code> otherwise
+	 */
+	Shell getDropDownShell() {
+		return fExpandBlock.getDropDownShell();
+	}
+
+	/**
+	 * Returns the drop down selection provider of this item.
+	 *
+	 * @return the selection provider of the drop down or <code>null</code>
+	 */
+	ISelectionProvider getDropDownSelectionProvider() {
+		return fExpandBlock.getDropDownSelectionProvider();
+	}
+
+	/**
+	 * Returns the bounds of this item.
+	 *
+	 * @return the bounds of this item
+	 */
+	public Rectangle getBounds() {
+		return fContainer.getBounds();
+	}
+
+	/**
+	 * Set the tool tip of the item to the given text.
+	 *
+	 * @param text the tool tip for the item
+	 */
+	public void setToolTip(String text) {
+		fDetailsBlock.setToolTip(text);
+	}
+
+	Color getForeground() {
+		return fDetailsBlock.getForeground();
+	}
+
+	void setForeground(Color color) {
+		fDetailsBlock.setForeground(color);
+	}
+
+	Color getBackground() {
+		return fDetailsBlock.getBackground();
+	}
+
+	void setBackground(Color color) {
+		fDetailsBlock.setBackground(color);
+	}
+
+	Font getFont() {
+		return fDetailsBlock.getFont();
+	}
+
+	void setFont(Font font) {
+		fDetailsBlock.setFont(font);
+	}
+
+	/*
+	 * @see org.eclipse.swt.widgets.Item#setText(java.lang.String)
+	 */
+	@Override
+	public void setText(String string) {
+		if (string == null) {
+			string = ""; //$NON-NLS-1$
+		}
+
+		super.setText(string);
+		fDetailsBlock.setText(string);
+
+		// more or less space might be required for the label
+		if (fIsLast)
+			fContainer.layout(true, true);
+	}
+
+	/*
+	 * @see org.eclipse.swt.widgets.Item#setImage(org.eclipse.swt.graphics.Image)
+	 */
+	@Override
+	public void setImage(Image image) {
+		super.setImage(image);
+		fDetailsBlock.setImage(image);
+	}
+
+}