Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import android.graphics.Bitmap;
import android.graphics.Color;

public class Main {
    public static final int SCAN_INTERVAL = 1;

    public static int[] findBoundsOfVisibleBitmap(Bitmap bitmap) {
        // Sanity check
        if (bitmap == null)
            return null;

        // Init data
        int bitmapWidth = bitmap.getWidth();
        int bitmapHeight = bitmap.getHeight();

        // Color
        int backgroundColor = Color.TRANSPARENT;

        // Bounds
        int xMin = Integer.MAX_VALUE;
        int xMax = Integer.MIN_VALUE;
        int yMin = Integer.MAX_VALUE;
        int yMax = Integer.MIN_VALUE;

        // Get pixel array
        int[][] bitmapArray = new int[bitmapHeight][bitmapWidth];
        for (int y = 0; y < bitmapHeight; y++) {
            bitmap.getPixels(bitmapArray[y], 0, bitmapWidth, 0, y, bitmapWidth, 1);
        }

        // Find bitmap bound
        boolean foundPixel = false;
        // Find xMin
        for (int x = 0; x < bitmapWidth; x += SCAN_INTERVAL) {
            boolean stop = false;
            for (int y = 0; y < bitmapHeight; y += SCAN_INTERVAL) {
                if (bitmapArray[y][x] != backgroundColor) {
                    xMin = x;
                    stop = true;
                    foundPixel = true;
                    break;
                }
            }
            if (stop)
                break;
        }

        // Image is empty...
        if (!foundPixel)
            return null;

        // Find yMin
        for (int y = 0; y < bitmapHeight; y += SCAN_INTERVAL) {
            boolean stop = false;
            for (int x = xMin; x < bitmapWidth; x += SCAN_INTERVAL) {
                if (bitmapArray[y][x] != backgroundColor) {
                    yMin = y;
                    stop = true;
                    break;
                }
            }
            if (stop)
                break;
        }

        // Find xMax
        for (int x = bitmapWidth - 1; x >= xMin; x -= SCAN_INTERVAL) {
            boolean stop = false;
            for (int y = yMin; y < bitmapHeight; y += SCAN_INTERVAL) {
                if (bitmapArray[y][x] != backgroundColor) {
                    xMax = x;
                    stop = true;
                    break;
                }
            }
            if (stop)
                break;
        }

        // Find yMax
        for (int y = bitmapHeight - 1; y >= yMin; y -= SCAN_INTERVAL) {
            boolean stop = false;
            for (int x = xMin; x <= xMax; x += SCAN_INTERVAL) {
                if (bitmapArray[y][x] != backgroundColor) {
                    yMax = y;
                    stop = true;
                    break;
                }
            }
            if (stop)
                break;
        }

        // Expand bitmap with offset
        int offset = SCAN_INTERVAL;
        int left = Math.max(xMin - offset, 0);
        int top = Math.max(yMin - offset, 0);
        int right = Math.min(xMax + offset, bitmapWidth);
        int bottom = Math.min(yMax + offset, bitmapHeight);

        int[] bound = { left, top, right, bottom };
        return bound;
    }
}