SCViewer/plugins/com.minres.scviewer.databas.../src/com/minres/scviewer/database/ui/swt/internal/ToolTipHandler.java

142 lines
4.5 KiB
Java

package com.minres.scviewer.database.swt.internal;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
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.Widget;
import com.minres.scviewer.database.swt.Constants;
import com.minres.scviewer.database.swt.ToolTipContentProvider;
import com.minres.scviewer.database.swt.ToolTipHelpTextProvider;
class ToolTipHandler {
private final Display display;
private Shell parentShell;
private Shell shell;
private Widget tipWidget; // widget this tooltip is hovering over
private Point tipPosition; // the position being hovered over
private static final int hoverYOffset = 1;
/**
* Creates a new tooltip handler
*
* @param parent the parent Shell
*/
public ToolTipHandler(Shell parent) {
display = parent.getDisplay();
parentShell = parent;
}
/**
* Enables customized hover help for a specified control
*
* @control the control on which to enable hoverhelp
*/
public void activateHoverHelp(final Control control) {
Listener listener = new Listener () {
Shell tip = null;
@Override
public void handleEvent (Event event) {
switch (event.type) {
case SWT.KeyDown:{
if (tip != null && tip.isVisible() && event.keyCode == SWT.F2) {
tip.setFocus();
break;
}
}
case SWT.Dispose:
case SWT.MouseMove:
case SWT.MouseDown: {
if (tip != null){
tip.dispose ();
tip = null;
tipWidget=null;
}
break;
}
case SWT.MouseHover: {
Object o = control.getData(Constants.CONTENT_PROVIDER_TAG);
if(o != null && o instanceof ToolTipContentProvider) {
ToolTipContentProvider provider = ((ToolTipContentProvider)o);
Point pt = new Point (event.x, event.y);
tipPosition = control.toDisplay(pt);
if (tip != null && !tip.isDisposed ()) tip.dispose ();
tip = new Shell (parentShell, SWT.NO_FOCUS | SWT.TOOL);
tip.setBackground (display.getSystemColor (SWT.COLOR_INFO_BACKGROUND));
GridLayout layout = new GridLayout(1, true);
layout.verticalSpacing=0;
layout.horizontalSpacing=0;
layout.marginWidth = 0;
layout.marginHeight = 0;
tip.setLayout(layout);
boolean visible = provider.createContent(tip, pt);
tip.pack();
tip.setSize(tip.computeSize(SWT.DEFAULT, SWT.DEFAULT));
setHoverLocation(tip, tipPosition);
tip.setVisible (visible);
if(visible)
tipWidget=event.widget;
}
}
}
}
};
control.addListener (SWT.Dispose, listener);
control.addListener (SWT.KeyDown, listener);
//control.addListener (SWT.MouseMove, listener);
control.addListener (SWT.MouseHover, listener);
control.addListener (SWT.MouseDown, listener);
/*
* Trap F1 Help to pop up a custom help box
*/
control.addHelpListener(event -> {
if (tipWidget == null) return;
ToolTipHelpTextProvider handler = (ToolTipHelpTextProvider)tipWidget.getData(Constants.HELP_PROVIDER_TAG);
if (handler == null) return;
String text = handler.getHelpText(tipWidget);
if (text == null) return;
if (shell.isVisible()) {
shell.setVisible(false);
Shell helpShell = new Shell(parentShell, SWT.SHELL_TRIM);
helpShell.setLayout(new FillLayout());
Label label = new Label(helpShell, SWT.NONE);
label.setText(text);
helpShell.pack();
setHoverLocation(helpShell, tipPosition);
helpShell.open();
}
});
// control.addKeyListener(KeyListener.keyPressedAdapter( e-> {
// if (e.keyCode == SWT.F2 && shell.isVisible()) {
// shell.setFocus();
// }
// }));
}
/**
* Sets the location for a hovering shell
* @param shell the object that is to hover
* @param position the position of a widget to hover over
* @return the top-left location for a hovering box
*/
private void setHoverLocation(Shell shell, Point position) {
Rectangle displayBounds = shell.getDisplay().getBounds();
Rectangle shellBounds = shell.getBounds();
shellBounds.x = Math.max(Math.min(position.x, displayBounds.width - shellBounds.width), 0);
shellBounds.y = Math.max(Math.min(position.y + hoverYOffset, displayBounds.height - shellBounds.height), 0);
shell.setBounds(shellBounds);
}
}