Java tutorial
//package com.java2s; /* * Copyright 2013, Edmodo, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. * You may obtain a copy of the License in the LICENSE file, or 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. */ import android.graphics.Bitmap; import android.graphics.Rect; import android.view.View; public class Main { /** * Gets the rectangular position of a Bitmap if it were placed inside a View * with scale type set to {@link ImageView#ScaleType #CENTER_INSIDE}. * * @param bitmap the Bitmap * @param view the parent View of the Bitmap * @return the rectangular position of the Bitmap */ public static Rect getBitmapRectCenterInside(Bitmap bitmap, View view) { final int bitmapWidth = bitmap.getWidth(); final int bitmapHeight = bitmap.getHeight(); final int viewWidth = view.getWidth(); final int viewHeight = view.getHeight(); return getBitmapRectCenterInsideHelper(bitmapWidth, bitmapHeight, viewWidth, viewHeight); } /** * Gets the rectangular position of a Bitmap if it were placed inside a View * with scale type set to {@link ImageView#ScaleType #CENTER_INSIDE}. * * @param bitmapWidth the Bitmap's width * @param bitmapHeight the Bitmap's height * @param viewWidth the parent View's width * @param viewHeight the parent View's height * @return the rectangular position of the Bitmap */ public static Rect getBitmapRectCenterInside(int bitmapWidth, int bitmapHeight, int viewWidth, int viewHeight) { return getBitmapRectCenterInsideHelper(bitmapWidth, bitmapHeight, viewWidth, viewHeight); } /** * Helper that does the work of the above functions. Gets the rectangular * position of a Bitmap if it were placed inside a View with scale type set * to {@link ImageView#ScaleType #CENTER_INSIDE}. * * @param bitmapWidth the Bitmap's width * @param bitmapHeight the Bitmap's height * @param viewWidth the parent View's width * @param viewHeight the parent View's height * @return the rectangular position of the Bitmap */ private static Rect getBitmapRectCenterInsideHelper(int bitmapWidth, int bitmapHeight, int viewWidth, int viewHeight) { double resultWidth; double resultHeight; int resultX; int resultY; double viewToBitmapWidthRatio = Double.POSITIVE_INFINITY; double viewToBitmapHeightRatio = Double.POSITIVE_INFINITY; // Checks if either width or height needs to be fixed if (viewWidth < bitmapWidth) { viewToBitmapWidthRatio = (double) viewWidth / (double) bitmapWidth; } if (viewHeight < bitmapHeight) { viewToBitmapHeightRatio = (double) viewHeight / (double) bitmapHeight; } // If either needs to be fixed, choose smallest ratio and calculate from // there if (viewToBitmapWidthRatio != Double.POSITIVE_INFINITY || viewToBitmapHeightRatio != Double.POSITIVE_INFINITY) { if (viewToBitmapWidthRatio <= viewToBitmapHeightRatio) { resultWidth = viewWidth; resultHeight = (bitmapHeight * resultWidth / bitmapWidth); } else { resultHeight = viewHeight; resultWidth = (bitmapWidth * resultHeight / bitmapHeight); } } // Otherwise, the picture is within frame layout bounds. Desired width // is simply picture size else { resultHeight = bitmapHeight; resultWidth = bitmapWidth; } // Calculate the position of the bitmap inside the ImageView. if (resultWidth == viewWidth) { resultX = 0; resultY = (int) Math.round((viewHeight - resultHeight) / 2); } else if (resultHeight == viewHeight) { resultX = (int) Math.round((viewWidth - resultWidth) / 2); resultY = 0; } else { resultX = (int) Math.round((viewWidth - resultWidth) / 2); resultY = (int) Math.round((viewHeight - resultHeight) / 2); } final Rect result = new Rect(resultX, resultY, resultX + (int) Math.ceil(resultWidth), resultY + (int) Math.ceil(resultHeight)); return result; } }