Java tutorial
/* * Copyright 2000-2014 Vaadin Ltd. * * 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.vaadin.client.ui; import java.util.HashMap; import java.util.Iterator; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.ImageElement; import com.google.gwt.dom.client.NodeList; import com.google.gwt.dom.client.Style; import com.google.gwt.dom.client.Style.BorderStyle; import com.google.gwt.dom.client.Style.Position; import com.google.gwt.dom.client.Style.Unit; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Event; import com.google.gwt.user.client.ui.ComplexPanel; import com.google.gwt.user.client.ui.Widget; import com.vaadin.client.ApplicationConnection; import com.vaadin.client.BrowserInfo; import com.vaadin.client.ComponentConnector; import com.vaadin.client.StyleConstants; import com.vaadin.client.Util; import com.vaadin.client.VCaption; import com.vaadin.client.VCaptionWrapper; import com.vaadin.client.WidgetUtil; /** * Custom Layout implements complex layout defined with HTML template. * * @author Vaadin Ltd * */ public class VCustomLayout extends ComplexPanel { public static final String CLASSNAME = "v-customlayout"; /** Location-name to containing element in DOM map */ private final HashMap<String, Element> locationToElement = new HashMap<String, Element>(); /** Location-name to contained widget map */ final HashMap<String, Widget> locationToWidget = new HashMap<String, Widget>(); /** Widget to captionwrapper map */ private final HashMap<Widget, VCaptionWrapper> childWidgetToCaptionWrapper = new HashMap<Widget, VCaptionWrapper>(); /** * Unexecuted scripts loaded from the template. * <p> * For internal use only. May be removed or replaced in the future. */ public String scripts = ""; /** * Paintable ID of this paintable. * <p> * For internal use only. May be removed or replaced in the future. */ public String pid; /** For internal use only. May be removed or replaced in the future. */ public ApplicationConnection client; private boolean htmlInitialized = false; private Element elementWithNativeResizeFunction; private String height = ""; private String width = ""; public VCustomLayout() { setElement(DOM.createDiv()); // Clear any unwanted styling Style style = getElement().getStyle(); style.setBorderStyle(BorderStyle.NONE); style.setMargin(0, Unit.PX); style.setPadding(0, Unit.PX); if (BrowserInfo.get().isIE()) { style.setPosition(Position.RELATIVE); } setStyleName(CLASSNAME); } @Override public void setStyleName(String style) { super.setStyleName(style); addStyleName(StyleConstants.UI_LAYOUT); } /** * Sets widget to given location. * * If location already contains a widget it will be removed. * * @param widget * Widget to be set into location. * @param location * location name where widget will be added * * @throws IllegalArgumentException * if no such location is found in the layout. */ public void setWidget(Widget widget, String location) { if (widget == null) { return; } // If no given location is found in the layout, and exception is throws Element elem = locationToElement.get(location); if (elem == null && hasTemplate()) { throw new IllegalArgumentException("No location " + location + " found"); } // Get previous widget final Widget previous = locationToWidget.get(location); // NOP if given widget already exists in this location if (previous == widget) { return; } if (previous != null) { remove(previous); } // if template is missing add element in order if (!hasTemplate()) { elem = getElement(); } // Add widget to location super.add(widget, elem); locationToWidget.put(location, widget); } /** Initialize HTML-layout. */ public void initializeHTML(String template, String themeUri) { // Connect body of the template to DOM template = extractBodyAndScriptsFromTemplate(template); // TODO prefix img src:s here with a regeps, cannot work further with IE String relImgPrefix = WidgetUtil.escapeAttribute(themeUri + "/layouts/"); // prefix all relative image elements to point to theme dir with a // regexp search template = template.replaceAll("<((?:img)|(?:IMG))\\s([^>]*)src=\"((?![a-z]+:)[^/][^\"]+)\"", "<$1 $2src=\"" + relImgPrefix + "$3\""); // also support src attributes without quotes template = template.replaceAll("<((?:img)|(?:IMG))\\s([^>]*)src=[^\"]((?![a-z]+:)[^/][^ />]+)[ />]", "<$1 $2src=\"" + relImgPrefix + "$3\""); // also prefix relative style="...url(...)..." template = template.replaceAll("(<[^>]+style=\"[^\"]*url\\()((?![a-z]+:)[^/][^\"]+)(\\)[^>]*>)", "$1 " + relImgPrefix + "$2 $3"); getElement().setInnerHTML(template); // Remap locations to elements locationToElement.clear(); scanForLocations(getElement()); initImgElements(); elementWithNativeResizeFunction = DOM.getFirstChild(getElement()); if (elementWithNativeResizeFunction == null) { elementWithNativeResizeFunction = getElement(); } publishResizedFunction(elementWithNativeResizeFunction); htmlInitialized = true; } private native boolean uriEndsWithSlash() /*-{ var path = $wnd.location.pathname; if(path.charAt(path.length - 1) == "/") return true; return false; }-*/; /** For internal use only. May be removed or replaced in the future. */ public boolean hasTemplate() { return htmlInitialized; } /** Collect locations from template */ private void scanForLocations(Element elem) { if (elem.hasAttribute("location")) { final String location = elem.getAttribute("location"); locationToElement.put(location, elem); elem.setInnerHTML(""); } else { final int len = DOM.getChildCount(elem); for (int i = 0; i < len; i++) { scanForLocations(DOM.getChild(elem, i)); } } } /** * Evaluate given script in browser document. * <p> * For internal use only. May be removed or replaced in the future. */ public static native void eval(String script) /*-{ try { if (script != null) eval("{ var document = $doc; var window = $wnd; "+ script + "}"); } catch (e) { } }-*/; /** * Img elements needs some special handling in custom layout. Img elements * will get their onload events sunk. This way custom layout can notify * parent about possible size change. */ private void initImgElements() { NodeList<Element> nodeList = getElement().getElementsByTagName("IMG"); for (int i = 0; i < nodeList.getLength(); i++) { ImageElement img = ImageElement.as(nodeList.getItem(i)); DOM.sinkEvents(img, Event.ONLOAD); } } /** * Extract body part and script tags from raw html-template. * * Saves contents of all script-tags to private property: scripts. Returns * contents of the body part for the html without script-tags. Also replaces * all _UID_ tags with an unique id-string. * * @param html * Original HTML-template received from server * @return html that is used to create the HTMLPanel. */ private String extractBodyAndScriptsFromTemplate(String html) { // Replace UID:s html = html.replaceAll("_UID_", pid + "__"); // Exctract script-tags scripts = ""; int endOfPrevScript = 0; int nextPosToCheck = 0; String lc = html.toLowerCase(); String res = ""; int scriptStart = lc.indexOf("<script", nextPosToCheck); while (scriptStart > 0) { res += html.substring(endOfPrevScript, scriptStart); scriptStart = lc.indexOf(">", scriptStart); final int j = lc.indexOf("</script>", scriptStart); scripts += html.substring(scriptStart + 1, j) + ";"; nextPosToCheck = endOfPrevScript = j + "</script>".length(); scriptStart = lc.indexOf("<script", nextPosToCheck); } res += html.substring(endOfPrevScript); // Extract body html = res; lc = html.toLowerCase(); int startOfBody = lc.indexOf("<body"); if (startOfBody < 0) { res = html; } else { res = ""; startOfBody = lc.indexOf(">", startOfBody) + 1; final int endOfBody = lc.indexOf("</body>", startOfBody); if (endOfBody > startOfBody) { res = html.substring(startOfBody, endOfBody); } else { res = html.substring(startOfBody); } } return res; } /** Update caption for given widget */ public void updateCaption(ComponentConnector paintable) { Widget widget = paintable.getWidget(); if (widget.getParent() != this) { // Widget has not been added because the location was not found return; } VCaptionWrapper wrapper = childWidgetToCaptionWrapper.get(widget); if (VCaption.isNeeded(paintable.getState())) { if (wrapper == null) { // Add a wrapper between the layout and the child widget final String loc = getLocation(widget); super.remove(widget); wrapper = new VCaptionWrapper(paintable, client); super.add(wrapper, locationToElement.get(loc)); childWidgetToCaptionWrapper.put(widget, wrapper); } wrapper.updateCaption(); } else { if (wrapper != null) { // Remove the wrapper and add the widget directly to the layout final String loc = getLocation(widget); super.remove(wrapper); super.add(widget, locationToElement.get(loc)); childWidgetToCaptionWrapper.remove(widget); } } } /** Get the location of an widget */ public String getLocation(Widget w) { for (final Iterator<String> i = locationToWidget.keySet().iterator(); i.hasNext();) { final String location = i.next(); if (locationToWidget.get(location) == w) { return location; } } return null; } /** Removes given widget from the layout */ @Override public boolean remove(Widget w) { final String location = getLocation(w); if (location != null) { locationToWidget.remove(location); } final VCaptionWrapper cw = childWidgetToCaptionWrapper.get(w); if (cw != null) { childWidgetToCaptionWrapper.remove(w); return super.remove(cw); } else if (w != null) { return super.remove(w); } return false; } /** Adding widget without specifying location is not supported */ @Override public void add(Widget w) { throw new UnsupportedOperationException(); } /** Clear all widgets from the layout */ @Override public void clear() { super.clear(); locationToWidget.clear(); childWidgetToCaptionWrapper.clear(); } /** * This method is published to JS side with the same name into first DOM * node of custom layout. This way if one implements some resizeable * containers in custom layout he/she can notify children after resize. */ public void notifyChildrenOfSizeChange() { client.runDescendentsLayout(this); } @Override public void onDetach() { super.onDetach(); if (elementWithNativeResizeFunction != null) { detachResizedFunction(elementWithNativeResizeFunction); } } private native void detachResizedFunction(Element element) /*-{ element.notifyChildrenOfSizeChange = null; }-*/; private native void publishResizedFunction(Element element) /*-{ var self = this; element.notifyChildrenOfSizeChange = $entry(function() { self.@com.vaadin.client.ui.VCustomLayout::notifyChildrenOfSizeChange()(); }); }-*/; /** * In custom layout one may want to run layout functions made with * JavaScript. This function tests if one exists (with name "iLayoutJS" in * layouts first DOM node) and runs et. Return value is used to determine if * children needs to be notified of size changes. * <p> * Note! When implementing a JS layout function you most likely want to call * notifyChildrenOfSizeChange() function on your custom layouts main * element. That method is used to control whether child components layout * functions are to be run. * <p> * For internal use only. May be removed or replaced in the future. * * @param el * @return true if layout function exists and was run successfully, else * false. */ public native boolean iLayoutJS(com.google.gwt.user.client.Element el) /*-{ if(el && el.iLayoutJS) { try { el.iLayoutJS(); return true; } catch (e) { return false; } } else { return false; } }-*/; @Override public void onBrowserEvent(Event event) { super.onBrowserEvent(event); if (event.getTypeInt() == Event.ONLOAD) { Util.notifyParentOfSizeChange(this, true); event.cancelBubble(true); } } }