Synnefo » Pithos

/*

 * Copyright 2006 Robert Hanson <iamroberthanson AT gmail.com>

 *

 * 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 gr.ebs.gss.client;

import com.google.gwt.user.client.ui.FlexTable;

import com.google.gwt.user.client.ui.Grid;

import com.google.gwt.user.client.ui.Label;

import com.google.gwt.user.client.ui.VerticalPanel;

/**

 * <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

 */

public 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 = "Estimated time remaining: {0} Seconds";

        private String minutesMessage = "Estimated time remaining: {0} Minutes";

        private String hoursMessage = "Estimated 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 elementNo The number of elements (bars) to show on the progress bar

         * @param options The display options for the progress bar

         */

        public ProgressBar(int elementNo, 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

                elements = elementNo;

                // Styling

                remainLabel.setStyleName("progressbar-remaining");

                textLabel.setStyleName("progressbar-text");

                // Initialize the progress elements

                elementGrid = new Grid(1, elementNo);

                elementGrid.setStyleName("progressbar-inner");

                elementGrid.setCellPadding(0);

                elementGrid.setCellSpacing(0);

                for (int loop = 0; loop < elementNo; 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 elementNo The number of elements (bars) to show on the progress bar

         */

        public ProgressBar(int elementNo) {

                this(elementNo, 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 textLabel.getText();

        }

        /**

         * Set the text displayed above the progress bar

         *

         * @param text the text to set

         */

        public void setText(String text) {

                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 anHoursMessage the hours message to set

         */

        public void setHoursMessage(String anHoursMessage) {

                hoursMessage = anHoursMessage;

        }

        /**

         * 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 aMinutesMessage the minutes message to set

         */

        public void setMinutesMessage(String aMinutesMessage) {

                minutesMessage = aMinutesMessage;

        }

        /**

         * 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 aSecondsMessage the secondsMessage to set

         */

        public void setSecondsMessage(String aSecondsMessage) {

                secondsMessage = aSecondsMessage;

        }

}