com.darwinsys.swingui.layout.RelativeLayout Maven / Gradle / Ivy
package com.darwinsys.swingui.layout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.Point;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
/**
*
* RelativeLayout, a Relative Layout Manager for Java SE.
* Mainly for porting tired old code that uses x,y locations.
* You really can't just assign x,y locations to components
* in Java SE - it breaks badly when the user resizes (and you can
* not mandate that the user can't resize you -- see any book
* on UI design for that little discussion -- and can also look
* bad due to resolution independance. Symantec Cafe 1.x, for example,
* used to spit out unfortunate (and unmaintainable) code like this:
*
* setLayout(null);
* setSize(331,241);
* label1=new Label("Info Applet", Label.CENTER);
* add(label1);
* label1.setBounds(91,19,107,15);
*
*
* Bleaarrgghh!!!
* To make it work properly at all resolutions and survive
* user-initiated resize actions, change it to
*
* setLayout(new RelativeLayout(331,241,false);
* label1=new Label("Info Applet", Label.CENTER);
* add("91,19", label1);
*
* Note that it's actually less work to get it right.
* Symantec, Microsoft, and others, please take note!
* @author Ian Darwin, http://www.darwinsys.com/
*/
public class RelativeLayout implements LayoutManager {
/** requested absolute width of canvas */
protected int reqWid;
/** requested absolute height of canvas */
protected int reqHgt;
/** actual size width when laid out */
protected int curWid;
/** actual size height when laid out */
protected int curHgt;
/** to track Components added by named add form. */
protected List curComps = new ArrayList();
/**
* Constructs an RelativeLayout, given original hard-coded size of panel.
*/
public RelativeLayout(int wid, int ht) {
this.reqWid = wid;
this.reqHgt = ht;
}
/**
* Called by AWT when the user uses the form add(name, Component).
* Adds the specified component with the specified name to the layout.
*
* @param name String with location for component c
* Note: the "name" must contain x, y location, ie.,
*
add("" + 320 + "," + 100, new Button("Quit"));
*
or
*
add("320,100", new Button("Quit").
*
This adds the Button at x=320, y=100 when the Panel is
* at its original full size.
* @param comp Component to be added.
*/
public void addLayoutComponent(String name, Component comp) {
int x, y;
StringTokenizer st = new StringTokenizer(name, ",");
x = Integer.parseInt(st.nextToken());
y = Integer.parseInt(st.nextToken());
addLayoutComponent(comp, new Dimension(x, y));
}
/** This version is here in preparation for implementing LayoutManager2 */
public void addLayoutComponent(Component comp, Object constraint) {
Dimension d = (Dimension)constraint;
int x = d.width, y = d.height;
// System.out.println("Adding: Name " + name +"; obj " + c
// + "; x " + x + "; y " + y);
Tracker t = new Tracker(x, y, comp);
curComps.add(t);
}
/**
* Called by AWT to lay out the components
* in the target Container at its current size.
*
* @param target Container whose components are to be laid out.
*/
public void layoutContainer(Container target) {
Dimension targSize = target.getSize();
Insets ins = target.getInsets();
// System.out.println("layoutContainer: size " + targSize);
curWid = targSize.width;
curHgt = targSize.height;
float widRatio = (float)curWid / (float)reqWid;
float hgtRatio = (float)curHgt / (float)reqHgt;
for (int i = 0; i