--- /dev/null
+package org.argeo.cms.ui.widgets;
+
+import org.argeo.cms.swt.CmsSwtUtils;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.ShellAdapter;
+import org.eclipse.swt.events.ShellEvent;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Shell;
+
+/**
+ * Manages a lightweight shell which is related to a {@link Control}, typically
+ * in order to reproduce a dropdown semantic, but with more flexibility.
+ */
+public class ContextOverlay extends ScrolledPage {
+ private static final long serialVersionUID = 6702077429573324009L;
+
+// private Shell shell;
+ private Control control;
+
+ private int maxHeight = 400;
+
+ public ContextOverlay(Control control, int style) {
+ super(createShell(control, style), SWT.NONE);
+ Shell shell = getShell();
+ setLayoutData(CmsSwtUtils.fillAll());
+ // TODO make autohide configurable?
+ //shell.addShellListener(new AutoHideShellListener());
+ this.control = control;
+ control.addDisposeListener((e) -> {
+ dispose();
+ shell.dispose();
+ });
+ }
+
+ private static Composite createShell(Control control, int style) {
+ if (control == null)
+ throw new IllegalArgumentException("Control cannot be null");
+ if (control.isDisposed())
+ throw new IllegalArgumentException("Control is disposed");
+ Shell shell = new Shell(control.getShell(), SWT.NO_TRIM);
+ shell.setLayout(CmsSwtUtils.noSpaceGridLayout());
+ Composite placeholder = new Composite(shell, SWT.BORDER);
+ placeholder.setLayoutData(CmsSwtUtils.fillAll());
+ placeholder.setLayout(CmsSwtUtils.noSpaceGridLayout());
+ return placeholder;
+ }
+
+ public void show() {
+ Point relativeControlLocation = control.getLocation();
+ Point controlLocation = control.toDisplay(relativeControlLocation.x, relativeControlLocation.y);
+
+ int controlWidth = control.getBounds().width;
+
+ Shell shell = getShell();
+
+ layout(true, true);
+ shell.pack();
+ shell.layout(true, true);
+ int targetShellWidth = shell.getSize().x < controlWidth ? controlWidth : shell.getSize().x;
+ if (shell.getSize().y > maxHeight) {
+ shell.setSize(targetShellWidth, maxHeight);
+ } else {
+ shell.setSize(targetShellWidth, shell.getSize().y);
+ }
+
+ int shellHeight = shell.getSize().y;
+ int controlHeight = control.getBounds().height;
+ Point shellLocation = new Point(controlLocation.x, controlLocation.y + controlHeight);
+ int displayHeight = shell.getDisplay().getBounds().height;
+ if (shellLocation.y + shellHeight > displayHeight) {// bottom of page
+ shellLocation = new Point(controlLocation.x, controlLocation.y - shellHeight);
+ }
+ shell.setLocation(shellLocation);
+
+ if (getChildren().length != 0)
+ shell.open();
+ if (!control.isDisposed())
+ control.setFocus();
+ }
+
+ public void hide() {
+ getShell().setVisible(false);
+ onHide();
+ }
+
+ public boolean isShellVisible() {
+ if (isDisposed())
+ return false;
+ return getShell().isVisible();
+ }
+
+ /** to be overridden */
+ protected void onHide() {
+ // does nothing by default.
+ }
+
+ private class AutoHideShellListener extends ShellAdapter {
+ private static final long serialVersionUID = 7743287433907938099L;
+
+ @Override
+ public void shellDeactivated(ShellEvent e) {
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e1) {
+ // silent
+ }
+ if (!control.isDisposed() && !control.isFocusControl())
+ hide();
+ }
+ }
+}