Java tutorial
/* * Copyright 2008 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.google.gwt.user.client.ui; import com.google.gwt.dom.client.Element; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.ui.HasHorizontalAlignment.HorizontalAlignmentConstant; import com.google.gwt.user.client.ui.HasVerticalAlignment.VerticalAlignmentConstant; /** * A panel whose child widgets are contained within the cells of a table. Each * cell's size may be set independently. Each child widget can take up a subset * of its cell and can be aligned within it. * * <p> * Note: This class is not related to the * {@link com.google.gwt.cell.client.Cell} based data presentation widgets such * as {@link com.google.gwt.user.cellview.client.CellList} and * {@link com.google.gwt.user.cellview.client.CellTable}. * * <h3>Use in UiBinder Templates</h3> * <P> * When working with CellPanel subclasses in * {@link com.google.gwt.uibinder.client.UiBinder UiBinder} templates, wrap * child widgets in <code><g:cell></code> elements. (Note the lower case "c", * meant to signal that the cell is not a runtime object, and so cannot have a * <code>ui:field</code> attribute.) Cell elements can have attributes setting * their height, width and alignment. * <h4><g:cell> attributes</h4> * <p> * <dl> * <dt>horizontalAlignment * <dd>Interpreted as a static member of {@link HorizontalAlignmentConstant} and * used as the <code>align</code> argument to * {@link #setCellHorizontalAlignment} * <dt>verticalAlignment * <dd>Interpreted as a static member of {@link VerticalAlignmentConstant} and * used as the <code>align</code> argument to {@link #setCellVerticalAlignment} * <dt>width * <dd>Used as the <code>width</code> argument to {@link #setCellWidth} * <dt>height * <dd>Used as the <code>height</code> argument to {@link #setCellHeight} * </dl> * <p> * For example: * * <pre> * <g:HorizontalPanel> * <g:cell width='5em' horizontalAlignment='ALIGN_RIGHT'> * <g:Label ui:field='leftSide' /> * </g:cell> * <g:cell width='15em' horizontalAlignment='ALIGN_LEFT'> * <g:Label ui:field='rightSide' /> * </g:cell> * </g:HorizontalPanel> * </pre> */ public abstract class CellPanel extends ComplexPanel { private int spacing; private Element table, body; public CellPanel() { table = DOM.createTable(); body = DOM.createTBody(); DOM.appendChild(table, body); setElement(table); } /** * Gets the amount of spacing between this panel's cells. * * @return the inter-cell spacing, in pixels */ public int getSpacing() { return spacing; } /** * Sets the width of the border to be applied to all cells in this panel. * This is particularly useful when debugging layouts, in that it allows you * to see explicitly the cells that contain this panel's children. * * @param width * the width of the panel's cell borders, in pixels */ public void setBorderWidth(int width) { table.setPropertyString("border", "" + width); } /** * Overloaded version for IsWidget. * * @see #setCellHeight(Widget,String) */ public void setCellHeight(IsWidget w, String height) { this.setCellHeight(w.asWidget(), height); } /** * Sets the height of the cell associated with the given widget, related to * the panel as a whole. * * @param w * the widget whose cell height is to be set * @param height * the cell's height, in CSS units */ public void setCellHeight(Widget w, String height) { Element td = getWidgetTd(w); if (td != null) { td.setPropertyString("height", height); } } /** * Overloaded version for IsWidget. * * @see #setCellHorizontalAlignment(Widget,HasHorizontalAlignment.HorizontalAlignmentConstant) */ public void setCellHorizontalAlignment(IsWidget w, HorizontalAlignmentConstant align) { this.setCellHorizontalAlignment(w.asWidget(), align); } /** * Sets the horizontal alignment of the given widget within its cell. * * @param w * the widget whose horizontal alignment is to be set * @param align * the widget's horizontal alignment, as defined in * {@link HasHorizontalAlignment}. */ public void setCellHorizontalAlignment(Widget w, HorizontalAlignmentConstant align) { Element td = getWidgetTd(w); if (td != null) { setCellHorizontalAlignment(td, align); } } /** * Overloaded version for IsWidget. * * @see #setCellVerticalAlignment(Widget,HasVerticalAlignment.VerticalAlignmentConstant) */ public void setCellVerticalAlignment(IsWidget w, VerticalAlignmentConstant align) { this.setCellVerticalAlignment(w.asWidget(), align); } /** * Sets the vertical alignment of the given widget within its cell. * * @param w * the widget whose vertical alignment is to be set * @param align * the widget's vertical alignment, as defined in * {@link HasVerticalAlignment}. */ public void setCellVerticalAlignment(Widget w, HasVerticalAlignment.VerticalAlignmentConstant align) { Element td = getWidgetTd(w); if (td != null) { setCellVerticalAlignment(td, align); } } /** * Overloaded version for IsWidget. * * @see #setCellWidth(Widget,String) */ public void setCellWidth(IsWidget w, String width) { this.setCellWidth(w.asWidget(), width); } /** * Sets the width of the cell associated with the given widget, related to * the panel as a whole. * * @param w * the widget whose cell width is to be set * @param width * the cell's width, in CSS units */ public void setCellWidth(Widget w, String width) { Element td = getWidgetTd(w); if (td != null) { td.setPropertyString("width", width); } } /** * Sets the amount of spacing between this panel's cells. * * @param spacing * the inter-cell spacing, in pixels */ public void setSpacing(int spacing) { this.spacing = spacing; table.setPropertyInt("cellSpacing", spacing); } protected Element getBody() { return DOM.asOld(body); } protected Element getTable() { return DOM.asOld(table); } protected void setCellHorizontalAlignment(Element td, HorizontalAlignmentConstant align) { td.setPropertyString("align", align.getTextAlignString()); } protected void setCellVerticalAlignment(Element td, VerticalAlignmentConstant align) { td.getStyle().setProperty("verticalAlign", align.getVerticalAlignString()); } Element getWidgetTd(Widget w) { if (w.getParent() != this) { return null; } return DOM.getParent(w.getElement()); } }