Java/GWT/Progress Bar
GWT progress bar
/*
* Copyright 2006 Robert Hanson <iamroberthanson AT gmail.ru>
*
* 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.jexp.gwt.client;
import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.*;
import com.google.gwt.core.client.*;
public class GWTClient implements EntryPoint{
public void onModuleLoad() {
final ProgressBar progressBar = new ProgressBar(20
,ProgressBar.SHOW_TIME_REMAINING
+ProgressBar.SHOW_TEXT);
progressBar.setText("Doing something...");
RootPanel.get().add(progressBar);
Timer t = new Timer() {
public void run() {
int progress = progressBar.getProgress()+4;
if (progress>100) cancel();
progressBar.setProgress(progress);
}
};
t.scheduleRepeating(1000);
}
}
/**
* <P>A simple progress bar that uses table elements to show progress
* and with a basic time remaining calculation built in.
*
* <P>You can optionally display some text above the progress bar
* and/or display time remaining underneath the progress bar. To
* control the display of those features, set the options in the
* constructor as shown in the following usage example:
*
* <PRE>
* final ProgressBar progressBar = new ProgressBar(20
* ,ProgressBar.SHOW_TIME_REMAINING
* +ProgressBar.SHOW_TEXT);
* progressBar.setText("Doing something...");
* RootPanel.get().add(progressBar);
* Timer t = new Timer() {
* public void run() {
* int progress = progressBar.getProgress()+4;
* if (progress>100) cancel();
* progressBar.setProgress(progress);
* }
* };
* t.scheduleRepeating(1000);
* </PRE>
*
* <P>How the time remaining is displayed can be controlled by setting the
* relevant messages using the language of your choice.
*
* <P>The default setting for the messages are as follows:
*
* <PRE>
* setSecondsMessage("Time remaining: {0} Seconds");
* setMinutesMessage("Time remaining: {0} Minutes");
* setHoursMessage("Time remaining: {0} Hours");
* </PRE>
*
* <P>To reset the time remaining/set the start time, simply set the
* progress to zero.
*
* <P>Some basic CSS styling is available to control the text, border around the
* progress bar itself and the colour of the progress bar elements.
*
* <PRE>
* .progressbar-text {
* font-weight: bold;
* }
*
* .progressbar-remaining {
* font-size: 12px;
* font-style: italic;
* }
*
* .progressbar-outer {
* border: 1px solid black;
* }
*
* .progressbar-inner {
* border: 1px solid black;
* margin: 1px;
* }
*
* .progressbar-bar {
* width: 5px;
* height: 15px;
* margin: 1px;
* }
*
* .progressbar-fullbar {
* background: blue;
* }
*
* .progressbar-blankbar {
* background: #eee;
* }
*</PRE>
*
* <P>You can take advantage of the default style by adding the
* following to the head of your HTML page.
*
* <P><link rel="stylesheet" type="text/css" href="style/gwl-progressBar.css">
*
* <P>This style sheet also has two additional styles which you can use
* by adding the stye name to the widget. You can use either one of
* these, or use both combined.
*
* <PRE>
* ProgressBar progressBar = new ProgressBar(20);
* progressBar.addStyleName("progressbar-solid");
* progressBar.addStyleName("progressbar-noborder");
* </PRE>
*
* @author Bjarne Matzen - Bjarne[dot]Matzen[at]gmail[dot]com
*/
class ProgressBar extends VerticalPanel {
/**
* Option to show text label above progress bar
*/
public static final int SHOW_TEXT = 2;
/**
* Option to show time remaining
*/
public static final int SHOW_TIME_REMAINING = 1;
/**
* The time the progress bar was started
*/
private long startTime = System.currentTimeMillis();
/**
* The number of bar elements to show
*/
private int elements = 20;
/**
* Time element text
*/
private String secondsMessage = "Time remaining: {0} Seconds";
private String minutesMessage = "Time remaining: {0} Minutes";
private String hoursMessage = "Time remaining: {0} Hours";
/**
* Current progress (as a percentage)
*/
private int progress = 0;
/**
* This is the frame around the progress bar
*/
private FlexTable barFrame = new FlexTable();
/**
* This is the grid used to show the elements
*/
private Grid elementGrid;
/**
* This is the current text label below the progress bar
*/
private Label remainLabel = new Label();
/**
* This is the current text label above the progress bar
*/
private Label textLabel = new Label();
/**
* internal flags for options
*/
private boolean showRemaining = false;
private boolean showText = false;
/**
* Base constructor for this widget
*
* @param elements The number of elements (bars) to show on the progress bar
* @param options The display options for the progress bar
*/
public ProgressBar (int elements, int options)
{
// Read the options and set convenience variables
if ((options & SHOW_TIME_REMAINING) == SHOW_TIME_REMAINING) showRemaining = true;
if ((options & SHOW_TEXT) == SHOW_TEXT) showText = true;
// Set element count
this.elements = elements;
// Styling
remainLabel.setStyleName("progressbar-remaining");
textLabel.setStyleName("progressbar-text");
// Initialize the progress elements
elementGrid = new Grid(1, elements);
elementGrid.setStyleName("progressbar-inner");
elementGrid.setCellPadding(0);
elementGrid.setCellSpacing(0);
for (int loop = 0; loop < elements; loop++) {
Grid elm = new Grid(1, 1);
//elm.setHTML(0, 0, " ");
elm.setHTML(0, 0, "");
elm.setStyleName("progressbar-blankbar");
elm.addStyleName("progressbar-bar");
elementGrid.setWidget(0, loop, elm);
}
// Create the container around the elements
Grid containerGrid = new Grid(1,1);
containerGrid.setCellPadding(0);
containerGrid.setCellSpacing(0);
containerGrid.setWidget(0, 0, elementGrid);
containerGrid.setStyleName("progressbar-outer");
//containerGrid.setBorderWidth(1);
// Set up the surrounding flex table based on the options
int row = 0;
if (showText) barFrame.setWidget(row++, 0, textLabel);
barFrame.setWidget(row++, 0, containerGrid);
if (showRemaining) barFrame.setWidget(row++, 0, remainLabel);
barFrame.setWidth("100%");
// Add the frame to the panel
this.add(barFrame);
// Initialize progress bar
setProgress(0);
}
/**
* Constructor without options
*
* @param elements The number of elements (bars) to show on the progress bar
*/
public ProgressBar (int elements)
{
this(elements, 0);
}
/**
* Set the current progress as a percentage
*
* @param percentage Set current percentage for the progress bar
*/
public void setProgress (int percentage)
{
// Make sure we are error-tolerant
if (percentage > 100) percentage = 100;
if (percentage < 0) percentage = 0;
// Set the internal variable
progress = percentage;
// Update the elements in the progress grid to
// reflect the status
int completed = elements * percentage / 100;
for (int loop = 0; loop < elements; loop++) {
Grid elm = (Grid) elementGrid.getWidget(0, loop);
if (loop < completed) {
elm.setStyleName("progressbar-fullbar");
elm.addStyleName("progressbar-bar");
}
else {
elm.setStyleName("progressbar-blankbar");
elm.addStyleName("progressbar-bar");
}
}
if (percentage > 0) {
// Calculate the new time remaining
long soFar = (System.currentTimeMillis() - startTime) / 1000;
long remaining = soFar * (100 - percentage) / percentage;
// Select the best UOM
String remainText = secondsMessage;
if (remaining > 120) {
remaining = remaining / 60;
remainText = minutesMessage;
if (remaining > 120) {
remaining = remaining / 60;
remainText = hoursMessage;
}
}
// Locate the position to insert out time remaining
int pos = remainText.indexOf("{0}");
if (pos >= 0) {
String trail = "";
if (pos + 3 < remainText.length()) trail = remainText.substring(pos + 3);
remainText = remainText.substring(0, pos) + remaining + trail;
}
// Set the label
remainLabel.setText(remainText);
}
else {
// If progress is 0, reset the start time
startTime = System.currentTimeMillis();
}
}
/**
* Get the current progress as a percentage
*
* @return Current percentage for the progress bar
*/
public int getProgress ()
{
return (progress);
}
/**
* Get the text displayed above the progress bar
*
* @return the text
*/
public String getText ()
{
return this.textLabel.getText();
}
/**
* Set the text displayed above the progress bar
*
* @param text the text to set
*/
public void setText (String text)
{
this.textLabel.setText(text);
}
/**
* Get the message used to format the time remaining text
* for hours
*
* @return the hours message
*/
public String getHoursMessage ()
{
return hoursMessage;
}
/**
* Set the message used to format the time remaining text
* below the progress bar. There are 3 messages used for
* hours, minutes and seconds respectively.
*
* The message must contain a placeholder for the value. The
* placeholder must be {0}. For example, the following is
* a valid message:
*
* "Hours remaining: {0}"
*
* @param hoursMessage the hours message to set
*/
public void setHoursMessage (String hoursMessage)
{
this.hoursMessage = hoursMessage;
}
/**
* Get the message used to format the time remaining text
* for minutes
*
* @return the minutesMessage
*/
public String getMinutesMessage ()
{
return minutesMessage;
}
/**
* Set the message used to format the time remaining text
* below the progress bar. There are 3 messages used for
* hours, minutes and seconds respectively.
*
* The message must contain a placeholder for the value. The
* placeholder must be {0}. For example, the following is
* a valid message:
*
* "Minutes remaining: {0}"
*
* @param minutesMessage the minutes message to set
*/
public void setMinutesMessage (String minutesMessage)
{
this.minutesMessage = minutesMessage;
}
/**
* Get the message used to format the time remaining text
* for seconds
*
* @return the secondsMessage
*/
public String getSecondsMessage ()
{
return secondsMessage;
}
/**
* Set the message used to format the time remaining text
* below the progress bar. There are 3 messages used for
* hours, minutes and seconds respectively.
*
* The message must contain a placeholder for the value. The
* placeholder must be {0}. For example, the following is
* a valid message:
*
* "Seconds remaining: {0}"
*
* @param secondsMessage the secondsMessage to set
*/
public void setSecondsMessage (String secondsMessage)
{
this.secondsMessage = secondsMessage;
}
}
