[官方Demo]Bit地图ScalingDemo

[官方Demo]BitmapScalingDemo

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/* * BitmapScalingDemo.java * * Copyright ?1998-2010 Research In Motion Ltd. *  * Note: For the sake of simplicity, this sample application may not leverage * resource bundles and resource strings.  However, it is STRONGLY recommended * that application developers make use of the localization features available * within the BlackBerry development platform to ensure a seamless application * experience across a variety of languages and geographies.  For more information * on localizing your application, please refer to the BlackBerry Java Development * Environment Development Guide associated with this release. */package com.rim.samples.device.ui.bitmapscalingdemo;import net.rim.device.api.system.*;import net.rim.device.api.ui.*;import net.rim.device.api.ui.container.*;import net.rim.device.api.ui.component.*;/** *  A sample application to demonstrate Bitmap scaling */public class BitmapScalingDemo extends UiApplication{    /**     * Entry point for application     * @param args Command line arguments (not used)     */    public static void main(String[] args)    {        // Create a new instance of the application and make the currently        // running thread the application's event dispatch thread.        BitmapScalingDemo app = new BitmapScalingDemo();        app.enterEventDispatcher();            }    /**     * Creates a new BitmapScalingDemo object     */    public BitmapScalingDemo()    {        pushScreen(new BitmapScalingDemoScreen());    }        /**     * MainScreen class for the BitmapScalingDemo application      */    static class BitmapScalingDemoScreen extends MainScreen    {        private static String LABEL_X = " x ";                /**         * Creates a new BitmapScalingDemoScreen object         */        BitmapScalingDemoScreen()        {            setTitle("Bitmap Scaling Demo");                         // Create a Bitmap from a project resource            Bitmap bitmapOrig = Bitmap.getBitmapResource("rim.png");                        // Create a Bitmap of arbitrary size            int scaledX = 175;            int scaledY = 50;            Bitmap bitmapScaled = new Bitmap(scaledX, scaledY);            // Scale the original Bitmap into the new Bitmap using            // a Lanczos filter.                        bitmapOrig.scaleInto(bitmapScaled, Bitmap.FILTER_LANCZOS);                                   // Display the original Bitmap on the screen            BitmapField bitmapFieldOrig = new BitmapField(bitmapOrig, Field.FOCUSABLE);            StringBuffer strBuff = new StringBuffer("Original - ");            strBuff.append(bitmapOrig.getWidth());            strBuff.append(LABEL_X);            strBuff.append(bitmapOrig.getHeight());                        add(new LabelField(strBuff.toString()));            add(bitmapFieldOrig);            add(new SeparatorField());                        // Display the scaled Bitmap on the screen            BitmapField bitmapFieldScaled1 = new BitmapField(bitmapScaled, Field.FOCUSABLE);            strBuff.delete(0, strBuff.length());            strBuff.append("\nScaled - ");            strBuff.append(bitmapScaled.getWidth());            strBuff.append(LABEL_X);            strBuff.append(bitmapScaled.getHeight());            strBuff.append(" - FILTER_LANCZOS - Aspect ratio not preserved");            add(new LabelField(strBuff.toString()));            add(bitmapFieldScaled1);                        add(new SeparatorField());                        // Redefine the scaled Bitmap            bitmapScaled = new Bitmap(scaledX, scaledY);                                    // Scale the original Bitmap into the new Bitmap using            // a bilinear filter and maintaining aspect ratio.                        bitmapOrig.scaleInto(bitmapScaled, Bitmap.FILTER_BILINEAR, Bitmap.SCALE_TO_FILL);                                               // Display the newly scaled Bitmap on the screen                        BitmapField bitmapFieldScaled2 = new BitmapField(bitmapScaled, Field.FOCUSABLE);            strBuff.delete(0, strBuff.length());            strBuff.append("\nScaled - ");            strBuff.append(bitmapScaled.getWidth());            strBuff.append(LABEL_X);            strBuff.append(bitmapScaled.getHeight());            strBuff.append(" - FILTER_BILINEAR - Aspect ratio preserved");                       add(new LabelField(strBuff.toString()));            add(bitmapFieldScaled2);                        add(new SeparatorField());                                  // Redefine the scaled Bitmap            bitmapScaled = new Bitmap(scaledX, scaledY);                         // Calculate fragment dimensions                      int fragmentWidth = bitmapOrig.getWidth() >> 1; // >> 1 equivalent to / 2                        int fragmentHeight = bitmapOrig.getHeight() >> 1; // >> 1 equivalent to / 2                        // Scale a fragment of the original Bitmap into the new Bitmap            // using a box filter.            bitmapOrig.scaleInto(0, 0, fragmentWidth, fragmentHeight, bitmapScaled, 0, 0, bitmapScaled.getWidth(), bitmapScaled.getHeight(), Bitmap.FILTER_BOX);                        // Display the newly scaled Bitmap on the screen                        BitmapField bitmapFieldScaled3 = new BitmapField(bitmapScaled, Field.FOCUSABLE);                        strBuff.delete(0, strBuff.length());            strBuff.append("\nScaled fragment ");            strBuff.append(fragmentWidth);            strBuff.append(LABEL_X);            strBuff.append(fragmentHeight);            strBuff.append(" into ");            strBuff.append(bitmapScaled.getWidth());             strBuff.append(LABEL_X);            strBuff.append(bitmapScaled.getHeight());             strBuff.append(" - FILTER_BOX");                                  add(new LabelField(strBuff.toString()));            add(bitmapFieldScaled3);        }            }}

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