/*
* Ext GWT - Ext for GWT
* Copyright(c) 2007-2009, Ext JS, LLC.
* licensing@extjs.com
*
* http://extjs.com/license
*/
package com.extjs.gxt.ui.client.widget.layout;
import com.extjs.gxt.ui.client.core.El;
import com.extjs.gxt.ui.client.util.Rectangle;
import com.extjs.gxt.ui.client.util.Size;
import com.extjs.gxt.ui.client.widget.Component;
import com.extjs.gxt.ui.client.widget.Container;
import com.extjs.gxt.ui.client.widget.Layout;
/**
* This is a layout that enables anchoring of contained widgets relative to the
* container's dimensions. If the container is resized, all anchored items are
* automatically re-rendered according to their anchor rules.
*
* <p />
* Child Widgets are:
* <ul>
* <li><b>Sized</b> : Yes - relative to parent container</li>
* <li><b>Positioned</b> : No - child widgets will flow</li>
* </ul>
*
* <p />
* By default, AnchorLayout will calculate anchor measurements based on the size
* of the container itself. However, if <code>anchorSize</code> is specified,
* the layout will use it as a virtual container for the purposes of calculating
* anchor measurements based on it instead, allowing the container to be sized
* independently of the anchoring logic if necessary.
*
* <p />
* The items added to an AnchorLayout can also supply an anchoring-specific
* layout property (see {@link AnchorData#setAnchorSpec(String)}) which is a
* string containing two values: the horizontal anchor value and the vertical
* anchor value (for example, '100% 50%'). This value is what tells the layout
* how the item should be anchored to the container. The following types of
* anchor values are supported:
* <ul>
* <li><b>Percentage</b> : Any value between 1 and 100, expressed as a
* percentage. The first anchor is the percentage width that the item should
* take up within the container, and the second is the percentage height.
* Example: '100% 50%' would render an item the complete width of the container
* and 1/2 its height. If only one anchor value is supplied it is assumed to be
* the width value and the height will default to auto.</li>
* <li><b>Offsets</b> : Any positive or negative integer value. The first anchor
* is the offset from the right edge of the container, and the second is the
* offset from the bottom edge. Example: '-50 -100' would render an item the
* complete width of the container minus 50 pixels and the complete height minus
* 100 pixels. If only one anchor value is supplied it is assumed to be the
* right offset value and the bottom offset will default to 0.</li>
* </ul>
*
* <p />
* Anchor values can also be mixed as needed. For example, '-50 75%' would
* render the width offset from the container right edge by 50 pixels and 75% of
* the container's height.
*/
public class AnchorLayout extends Layout {
private Size anchorSize;
public AnchorLayout() {
monitorResize = true;
}
protected int adjustWidthAnchor(int width, Component comp) {
return width;
}
@Override
protected void onLayout(Container<?> container, El target) {
super.onLayout(container, target);
Size size = target.getStyleSize();
Rectangle rect = target.getBounds(true);
rect.width = size.width;
rect.height = size.height;
int w = rect.width, h = rect.height;
if (w < 20 || h < 20) {
return;
}
int aw, ah;
if (anchorSize != null) {
aw = anchorSize.width;
ah = anchorSize.height;
} else {
aw = rect.width;
ah = rect.height;
}
int len = container.getItemCount();
for (int i = 0; i < len; i++) {
Component comp = container.getItem(i);
AnchorData data = (AnchorData) getLayoutData(comp);
if (data == null && comp.getData("anchorSpec") != null) {
data = new AnchorData();
data.setAnchorSpec((String) comp.getData("anchorSpec"));
}
if (data != null) {
String anchor = data.getAnchorSpec();
if (anchor != null) {
String[] vs = anchor.split(" ");
int cw = parseAnchor(vs[0], w, aw, aw);
int ch = -1;
if (vs.length > 1) {
ch = parseAnchor(vs[1], h, ah, ah);
}
cw -= getSideMargins(comp);
ch -= comp.el().getMargins("tb");
cw = adjustWidthAnchor(cw, comp);
setSize(comp, cw, ch);
}
}
}
}
private native boolean standard(String a) /*-{
if(/^(r|right|b|bottom)$/i.test(a)){
return true;
} else {
return false;
}
}-*/;
/**
* Sets a virtual container for the layout to use.
*
* @param anchorSize the anchor size
*/
public void setAnchorSize(Size anchorSize) {
this.anchorSize = anchorSize;
}
/**
* Returns the anchor size.
*
* @return the anchor size
*/
public Size getAnchorSize() {
return anchorSize;
}
private int parseAnchor(String a, int v, int start, int cstart) {
if (a != null && !a.equals("none")) {
if (standard(a)) {
int diff = cstart - start;
return v - diff;
} else if (a.indexOf("%") != -1) {
double ratio = Float.parseFloat(a.replaceAll("%", "")) * .01;
return (int) Math.floor(v * ratio);
} else {
try {
int val = Integer.parseInt(a, 10);
return v + val;
} catch (Exception e) {
}
}
}
return -1;
}
}