Android Open Source - AsciiCamera Android Utils

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License

The source code is released under:

Apache License

Java Source Code

// Copyright (C) 2014 Bruno Ramalhete
/*from   w w w  .j  av  a  2  s.co m*/
package com.spectralsoftware.util;

import java.io.FileNotFoundException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.view.View;

public class AndroidUtils {

    /** Adds a click listener to the given view which invokes the method named by methodName on the given target.
     * The method must be public and take no arguments.
     */
    public static void bindOnClickListener(final Object target, View view, String methodName) {
        final Method method;
        try {
            method = target.getClass().getMethod(methodName);
        }
        catch(Exception ex) {
            throw new IllegalArgumentException(ex);
        }
        view.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                try {
                    method.invoke(target);
                }
                catch(Exception ex) {
                    throw new RuntimeException(ex);
                }
            }
        });
    }

    public static interface MediaScannerCallback {
        public void mediaScannerCompleted(String scanPath, Uri scanURI);
    }

    /** Notifies the OS to index the new image, so it shows up in Gallery. Allows optional callback method to notify client when
     * the scan is completed, e.g. so it can access the "content" URI that gets assigned.
     */
    public static void scanSavedMediaFile(final Context context, final String path, final MediaScannerCallback callback) {
        // silly array hack so closure can reference scannerConnection[0] before it's created 
        final MediaScannerConnection[] scannerConnection = new MediaScannerConnection[1];
        try {
            MediaScannerConnection.MediaScannerConnectionClient scannerClient = new MediaScannerConnection.MediaScannerConnectionClient() {
                public void onMediaScannerConnected() {
                    scannerConnection[0].scanFile(path, null);
                }

                public void onScanCompleted(String scanPath, Uri scanURI) {
                    scannerConnection[0].disconnect();
                    if (callback!=null) {
                        callback.mediaScannerCompleted(scanPath, scanURI);
                    }
                }
            };
            scannerConnection[0] = new MediaScannerConnection(context, scannerClient);
            scannerConnection[0].connect();
        }
        catch(Exception ignored) {}
    }
    
    public static void scanSavedMediaFile(final Context context, final String path) {
        scanSavedMediaFile(context, path, null);
    }
    
    /** Returns a BitmapFactory.Options object containing the size of the image at the given URI,
     * without actually loading the image.
     */
    public static BitmapFactory.Options computeBitmapSizeFromURI(Context context, Uri imageURI) throws FileNotFoundException {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(context.getContentResolver().openInputStream(imageURI), null, options);
        return options;
    }
    
    /** Returns a Bitmap from the given URI that may be scaled by an integer factor to reduce its size,
     * while staying as least as large as the width and height parameters.
     */
    public static Bitmap scaledBitmapFromURIWithMinimumSize(Context context, Uri imageURI, int width, int height) throws FileNotFoundException {
        BitmapFactory.Options options = computeBitmapSizeFromURI(context, imageURI);
        options.inJustDecodeBounds = false;
        
        float wratio = 1.0f*options.outWidth / width;
        float hratio = 1.0f*options.outHeight / height;        
        options.inSampleSize = (int)Math.min(wratio, hratio);
        
        return BitmapFactory.decodeStream(context.getContentResolver().openInputStream(imageURI), null, options);        
    }
    
    /** Given a width and height, fills output array with scaled width and height values 
     * such that one of the values is exactly equal to the given maximum width or height, 
     * and the other value is less than or equal to the maximum.
     */
    public static void getScaledWidthAndHeightToMaximum(
            int width, int height, int maxWidth, int maxHeight, int[] output) {
        output[0] = width;
        output[1] = height;
        // common cases: if one dimension fits exactly and the other is smaller, return unmodified
        if (width==maxWidth && height<=maxHeight) return;
        if (height==maxHeight && width<=maxWidth) return;
        float wratio = ((float)width)/maxWidth;
        float hratio = ((float)height)/maxHeight;
        if (wratio<=hratio) {
            // scale to full height, partial width
            output[0] = (int)(width/hratio);
            output[1] = maxHeight;
        }
        else {
            // scale to full width, partial height
            output[0] = maxWidth;
            output[1] = (int)(height/wratio);
        }
    }
    
    public static int[] scaledWidthAndHeightToMaximum(int width, int height, int maxWidth, int maxHeight) {
        int[] output = new int[2];
        getScaledWidthAndHeightToMaximum(width, height, maxWidth, maxHeight, output);
        return output;
    }
    
    /** On API level 14 (ICS) or higher, calls view.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE)
     * and returns true. On earlier API versions, does nothing and returns false.
     */
    public static boolean setSystemUiLowProfile(View view) {
      return setSystemUiVisibility(view, "SYSTEM_UI_FLAG_LOW_PROFILE");
    }
    
    static boolean setSystemUiVisibility(View view, String flagName) {
      try {
        Method setUiMethod = View.class.getMethod("setSystemUiVisibility", int.class);
        Field flagField = View.class.getField(flagName);
        setUiMethod.invoke(view, flagField.get(null));
        return true;
      }
      catch(Exception ex) {
        return false;
      }
    }
    
    /** Returns the estimated memory usage in bytes for a bitmap. Calls bitmap.getByteCount() if that method
     * is available (in API level 12 or higher), otherwise returns 4 times the number of pixels in the bitmap.
     */
    public static int getBitmapByteCount(Bitmap bitmap) {
        try {
            Method byteCountMethod = Bitmap.class.getMethod("getByteCount");
            return (Integer)byteCountMethod.invoke(bitmap);
        }
        catch(Exception ex) {
            return 4 * bitmap.getWidth() * bitmap.getHeight();
        }
    }
}

Java Source Code List

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