itogglestrategy.java

来自「利用它可以做出非常漂亮的swt界面,包含的组件有PShelf Plist」· Java 代码 · 共 53 行

package com.swtplus.widgets.toggle;

import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Widget;

/**
 * An IToggleStrategy tells a parent widget how to size and draw
 * the toggle.  In other words, an IToggleStrategy is not an actual 
 * widget, but a drawing strategy that another widget can use to paint
 * a toggle within its bounds.
 * 
 * @author chris
 */
public interface IToggleStrategy {
	
	/**
	 * Paints the toggle.  All drawing/painting should be done on the passed
	 * GC.  This GC is created on the parent widget.  Therefore this method needs to
	 * respect the location of the toggle within the parent.  That is, you will 
	 * need to offset your x and y positions based on the location set by the 
	 * parent widget (using the setLocation method).
	 * <p>
	 * The GCPlus class can be used to make the offets easier.  GCPlus can be 
	 * constructed with an x and y offset to be used for all subsequent calls.
	 * 
	 * @param parent the parent widget which the toggle is actually painting on
	 * @param gc the GC to paint the toggle with
	 * @param expanded true for expanded, false for collapsed
	 * @param hasFocus true if the parent widget has focus
	 * @param hovering true if the mouse is hovering over the toggle image
	 */
	public abstract void paint(Widget parent, GC gc,boolean expanded,boolean hasFocus, boolean hovering);
	
	/**
	 * Returns the size of the toggle image.  A toggle is expected to be a set
	 * size that does not change based on the expanded/collapsed state.
	 */
	public abstract Point getSize();
	
	/**
	 * Sets the location of the toggle image within the parent widget.  Use the
	 * location set here to offset the x and y positions within the paint method.
	 */
	public abstract void setLocation(Point p);
	
	/**
	 * Returns the current location.
	 */
	public abstract Point getLocation();

}