Java tutorial
/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- * ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (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.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla Android code. * * The Initial Developer of the Original Code is Mozilla Foundation. * Portions created by the Initial Developer are Copyright (C) 2011 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Kartikaya Gupta <kgupta@mozilla.com> * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ package org.mozilla.gecko.gfx; import org.mozilla.gecko.FloatUtils; import android.graphics.Point; import android.graphics.PointF; import android.graphics.Rect; import android.graphics.RectF; import org.json.JSONException; import org.json.JSONObject; public final class RectUtils { public static Rect create(JSONObject json) { try { int x = json.getInt("x"); int y = json.getInt("y"); int width = json.getInt("width"); int height = json.getInt("height"); return new Rect(x, y, x + width, y + height); } catch (JSONException e) { throw new RuntimeException(e); } } public static Rect contract(Rect rect, int lessWidth, int lessHeight) { float halfLessWidth = lessWidth / 2.0f; float halfLessHeight = lessHeight / 2.0f; return new Rect(Math.round(rect.left + halfLessWidth), Math.round(rect.top + halfLessHeight), Math.round(rect.right - halfLessWidth), Math.round(rect.bottom - halfLessHeight)); } public static RectF contract(RectF rect, float lessWidth, float lessHeight) { float halfLessWidth = lessWidth / 2; float halfLessHeight = lessHeight / 2; return new RectF(rect.left + halfLessWidth, rect.top + halfLessHeight, rect.right - halfLessWidth, rect.bottom - halfLessHeight); } public static RectF expand(RectF rect, float moreWidth, float moreHeight) { float halfMoreWidth = moreWidth / 2; float halfMoreHeight = moreHeight / 2; return new RectF(rect.left - halfMoreWidth, rect.top - halfMoreHeight, rect.right + halfMoreWidth, rect.bottom + halfMoreHeight); } public static RectF intersect(RectF one, RectF two) { float left = Math.max(one.left, two.left); float top = Math.max(one.top, two.top); float right = Math.min(one.right, two.right); float bottom = Math.min(one.bottom, two.bottom); return new RectF(left, top, Math.max(right, left), Math.max(bottom, top)); } public static RectF scale(RectF rect, float scale) { float x = rect.left * scale; float y = rect.top * scale; return new RectF(x, y, x + (rect.width() * scale), y + (rect.height() * scale)); } /** Returns the nearest integer rect of the given rect. */ public static Rect round(RectF rect) { return new Rect(Math.round(rect.left), Math.round(rect.top), Math.round(rect.right), Math.round(rect.bottom)); } public static IntSize getSize(Rect rect) { return new IntSize(rect.width(), rect.height()); } public static Point getOrigin(Rect rect) { return new Point(rect.left, rect.top); } public static PointF getOrigin(RectF rect) { return new PointF(rect.left, rect.top); } /* * Returns the rect that represents a linear transition between `from` and `to` at time `t`, * which is on the scale [0, 1). */ public static RectF interpolate(RectF from, RectF to, float t) { return new RectF(FloatUtils.interpolate(from.left, to.left, t), FloatUtils.interpolate(from.top, to.top, t), FloatUtils.interpolate(from.right, to.right, t), FloatUtils.interpolate(from.bottom, to.bottom, t)); } public static boolean fuzzyEquals(RectF a, RectF b) { return FloatUtils.fuzzyEquals(a.top, b.top) && FloatUtils.fuzzyEquals(a.left, b.left) && FloatUtils.fuzzyEquals(a.right, b.right) && FloatUtils.fuzzyEquals(a.bottom, b.bottom); } }