Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (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.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. */ package android.graphics; import android.os.Parcel; import android.os.Parcelable; /** * PointF holds two float coordinates */ public class PointF implements Parcelable { public float x; public float y; public PointF() { } public PointF(float x, float y) { this.x = x; this.y = y; } public PointF(Point p) { this.x = p.x; this.y = p.y; } /** * Set the point's x and y coordinates */ public final void set(float x, float y) { this.x = x; this.y = y; } /** * Set the point's x and y coordinates to the coordinates of p */ public final void set(PointF p) { this.x = p.x; this.y = p.y; } public final void negate() { x = -x; y = -y; } public final void offset(float dx, float dy) { x += dx; y += dy; } /** * Returns true if the point's coordinates equal (x,y) */ public final boolean equals(float x, float y) { return this.x == x && this.y == y; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; PointF pointF = (PointF) o; if (Float.compare(pointF.x, x) != 0) return false; if (Float.compare(pointF.y, y) != 0) return false; return true; } @Override public int hashCode() { int result = (x != +0.0f ? Float.floatToIntBits(x) : 0); result = 31 * result + (y != +0.0f ? Float.floatToIntBits(y) : 0); return result; } @Override public String toString() { return "PointF(" + x + ", " + y + ")"; } /** * Return the euclidian distance from (0,0) to the point */ public final float length() { return length(x, y); } /** * Returns the euclidian distance from (0,0) to (x,y) */ public static float length(float x, float y) { return (float) Math.hypot(x, y); } /** * Parcelable interface methods */ @Override public int describeContents() { return 0; } /** * Write this point to the specified parcel. To restore a point from * a parcel, use readFromParcel() * @param out The parcel to write the point's coordinates into */ @Override public void writeToParcel(Parcel out, int flags) { out.writeFloat(x); out.writeFloat(y); } public static final Parcelable.Creator<PointF> CREATOR = new Parcelable.Creator<PointF>() { /** * Return a new point from the data in the specified parcel. */ public PointF createFromParcel(Parcel in) { PointF r = new PointF(); r.readFromParcel(in); return r; } /** * Return an array of rectangles of the specified size. */ public PointF[] newArray(int size) { return new PointF[size]; } }; /** * Set the point's coordinates from the data stored in the specified * parcel. To write a point to a parcel, call writeToParcel(). * * @param in The parcel to read the point's coordinates from */ public void readFromParcel(Parcel in) { x = in.readFloat(); y = in.readFloat(); } }