Java tutorial
/* * Sencha GXT 2.3.1 - Sencha for GWT * Copyright(c) 2007-2013, Sencha, Inc. * licensing@sencha.com * * http://www.sencha.com/products/gxt/license/ */ package com.extjs.gxt.ui.client.widget; import com.extjs.gxt.ui.client.GXT; import com.extjs.gxt.ui.client.Style; import com.extjs.gxt.ui.client.core.CompositeElement; import com.extjs.gxt.ui.client.core.El; import com.extjs.gxt.ui.client.core.Template; import com.extjs.gxt.ui.client.event.ComponentEvent; import com.extjs.gxt.ui.client.event.Events; import com.extjs.gxt.ui.client.util.Params; import com.extjs.gxt.ui.client.util.Util; import com.google.gwt.user.client.Element; import com.google.gwt.user.client.Timer; import com.google.gwt.user.client.ui.Accessibility; /** * An updateable progress bar component. The progress bar supports two different * modes: manual and automatic. * * <p /> * In manual mode, you are responsible for showing, updating (via * {@link #updateProgress}) and clearing the progress bar as needed from your * own code. This method is most appropriate when you want to show progress * throughout an operation that has predictable points of interest at which you * can update the control. * * <p /> * In automatic mode, you simply call {@link #auto} and let the progress bar run * indefinitely, only clearing it once the operation is complete. You can * optionally have the progress bar wait for a specific amount of time and then * clear itself. Automatic mode is most appropriate for timed operations or * asynchronous operations in which you have no need for indicating intermediate * progress. * * <dl> * <dt>Inherited Events:</dt> * <dd>BoxComponent Move</dd> * <dd>BoxComponent Resize</dd> * <dd>Component Enable</dd> * <dd>Component Disable</dd> * <dd>Component BeforeHide</dd> * <dd>Component Hide</dd> * <dd>Component BeforeShow</dd> * <dd>Component Show</dd> * <dd>Component Attach</dd> * <dd>Component Detach</dd> * <dd>Component BeforeRender</dd> * <dd>Component Render</dd> * <dd>Component BrowserEvent</dd> * <dd>Component BeforeStateRestore</dd> * <dd>Component StateRestore</dd> * <dd>Component BeforeStateSave</dd> * <dd>Component SaveState</dd> * </dl> */ public class ProgressBar extends BoxComponent { private int duration = Style.DEFAULT; private int i = 0; private int increment = 10; private int interval = 300; private El progressBar; private boolean running; private String html = ""; private CompositeElement contentEl; private El textTopElem, textBackElem; private Timer timer; private double value; private boolean auto; /** * Creates a new progress bar. */ public ProgressBar() { baseStyle = "x-progress"; } /** * Initiates an auto-updating progress bar using the current duration, * increment, and interval. * * @return this */ public ProgressBar auto() { auto = true; if (timer == null) { timer = new Timer() { public void run() { int inc = getIncrement(); updateProgress(((((i++ + inc) % inc) + 1) * (100 / inc)) * .01, null); } }; } timer.scheduleRepeating(getInterval()); running = true; return this; } /** * Returns the duration. * * @return the duration */ public int getDuration() { return duration; } /** * Returns the bar's increment value. * * @return the increment the increment */ public int getIncrement() { return increment; } /** * Returns the bar's interval value. * * @return the interval in millseconds */ public int getInterval() { return interval; } /** * Returns the current value. * * @return the value */ public double getValue() { return value; } /** * Returns true if the progress bar is currently in a {@link #auto} operation. * * @return true if waiting, else false */ public boolean isRunning() { return running; } /** * Resets the progress bar value to 0 and text to empty string. * * @return this */ public ProgressBar reset() { updateProgress(0, ""); if (timer != null) { timer.cancel(); } running = false; return this; } /** * The length of time in milliseconds that the progress bar should run before * resetting itself (defaults to DEFAULT, in which case it will run * indefinitely until reset is called) * * @param duration the duration in milliseconds */ public void setDuration(int duration) { this.duration = duration; } /** * The number of progress update segments to display within the progress bar * (defaults to 10). If the bar reaches the end and is still updating, it will * automatically wrap back to the beginning. * * @param increment the new increment */ public void setIncrement(int increment) { this.increment = increment; } /** * Sets the length of time in milliseconds between each progress update * (defaults to 300 ms). * * @param interval the interval to set */ public void setInterval(int interval) { this.interval = interval; } /** * Updates the progress bar value, and optionally its text. If the text * argument is not specified, any existing text value will be unchanged. To * blank out existing text, pass "". Note that even if the progress bar value * exceeds 1, it will never automatically reset -- you are responsible for * determining when the progress is complete and calling {@link #reset} to * clear and/or hide the control. * * @param value A value between 0 and 1 (e.g., .5, defaults to 0) * @param text The string to display in the progress text element or null. * @return this */ public ProgressBar updateProgress(double value, String text) { value = Math.min(Math.max(value, 0), 1); this.value = value; if (text != null) { updateText(text); } if (!rendered) { return this; } if (GXT.isAriaEnabled()) { int v = (int) (value * 100); if (!auto) { Accessibility.setState(getElement(), "aria-valuenow", "" + v); } if (text != null) { Accessibility.setState(getElement(), "aria-valuetext", "" + text); } } double w = Math.floor(value * el().firstChild().getWidth()); progressBar.setWidth((int) w); if (textTopElem != null && w != 0) { textTopElem.removeStyleName("x-hidden").setWidth((int) w, true); } else if (textTopElem != null && w == 0) { textTopElem.addStyleName("x-hidden"); } fireEvent(Events.Update, new ComponentEvent(this)); return this; } /** * Updates the progress bar text. If specified, textEl will be updated, * otherwise the progress bar itself will display the updated text. * * @param text The string to display in the progress text element */ public void updateText(String text) { updateHtml(El.toSafeHTML(text)); } /** * Updates the contents of the progress bar with the specified HTML. * * @param html the HTML string to render in the progress bar */ public void updateHtml(String html) { this.html = html; if (rendered) { contentEl.setInnerHtml(Util.isEmptyString(html) ? " " : html); } } @Override protected void onAttach() { super.onAttach(); update(); } @Override protected void onDetach() { super.onDetach(); if (isRunning()) { reset(); } } @Override protected void onRender(Element target, int index) { StringBuffer sb = new StringBuffer(); sb.append("<div class='{cls}-wrap'><div class='{cls}-inner'><div class='{cls}-bar'>"); sb.append("<div class='{cls}-text'><div> </div></div></div>"); sb.append("<div class='{cls}-text {cls}-text-back'><div> </div></div></div></div>"); Template t = new Template(sb.toString()); setElement(t.create(new Params("cls", baseStyle)), target, index); El inner = el().firstChild(); progressBar = inner.firstChild(); textTopElem = progressBar.firstChild(); textBackElem = inner.childNode(1); textTopElem.setStyleAttribute("zIndex", 99).addStyleName("x-hidden"); contentEl = new CompositeElement(); contentEl.add(textTopElem.firstChild().dom); contentEl.add(textBackElem.firstChild().dom); if (GXT.isHighContrastMode) { contentEl.getElement(0).getStyle().setProperty("backgroundColor", "#ffffff"); } if (GXT.isAriaEnabled()) { setAriaRole("progressbar"); if (!auto) { getAriaSupport().setState("aria-valuemin", "0"); getAriaSupport().setState("aria-valuemax", "100"); } } } @Override protected void onResize(int width, int height) { super.onResize(width, height); update(); } private void update() { contentEl.setWidth(el().firstChild().getWidth()); updateProgress(value, html); } }