Android uses property animations to customize the gradient background of a view

Customize the view gradient background while listening gestures automatically generate small spheres.

The host activity is as follows:

Package Com.edaixi.tempbak;import Java.util.arraylist;import Android.animation.animator;import Android.animation.animatorlisteneradapter;import Android.animation.animatorset;import Android.animation.argbevaluator;import Android.animation.objectanimator;import Android.animation.ValueAnimator; Import Android.annotation.suppresslint;import Android.app.activity;import Android.content.context;import Android.graphics.canvas;import Android.graphics.paint;import Android.graphics.radialgradient;import Android.graphics.shader;import Android.graphics.drawable.shapedrawable;import Android.graphics.drawable.shapes.ovalshape;import Android.os.bundle;import Android.view.motionevent;import Android.view.view;import Android.view.window;import Android.view.animation.accelerateinterpolator;import Android.view.animation.decelerateinterpolator;import android.widget.LinearLayout; @SuppressLint ("Newapi") public Class Mainactivity extends activity {/** Called when the activity is first created. */@Overridepublicvoid OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Requestwindowfeature (window.feature_ No_title); Setcontentview (R.layout.activity_main); LinearLayout container = (linearlayout) Findviewbyid (R.id.container); Container.addview (new Myanimationview (This));} public class Myanimationview extends View {private static final int RED = 0xffff8080;private static final int BLUE = 0XFF8 080ff;private static final int CYAN = 0xff80ffff;private static final int GREEN = 0xff80ff80;public final Arraylist<sha peholder> balls = new arraylist<shapeholder> (); Animatorset animation = Null;public Myanimationview (context context) {super (context);/****************************** * * Set the background of the custom view, is a gradual process, with valueanimator implementation, Valueanimator is the core class of the property * Animation system, which contains most of the methods for configuring the properties Animation attribute, which requires a direct or indirectly using the Valueanimator class, the steps to use Valueanimator are as follows: * 1. Call Ofint in the Valueanimation class (int ... Values), OFfloat (String * propertyname,float...values) and other static party * methods instantiate the Valueanimator object, and set the property name, initial value or end value equivalent of the target attribute; * 2. Call the Addupdatelistener (Animatorupdatelistener * Mlistener) method to set the listener for the property change for the Valueanimator object * 3. Create a custom Interpolator, Call Setinterpolator (Timeinterpolator * value) to set the custom interpolator for valueaniamtor; (optional, do not set default defaults) * 4. Create a custom Typeevaluator , Call Setevaluator (Typeevaluator * value) to set the custom typeevaluator for valueanimator; (optional, do not set default defaults) * 5. In Animatorupdatelistener The implementation method in the target object sets the calculated property value for the property. * 6. Set the duration of the animation, whether repeat and repeat the number of properties; 7. Set the target object for Valueanimator and start the animation. * * ***************************************************************** */valueanimator ColorAnim = Objectanimator.ofint (This, "BackgroundColor", RED, BLUE); coloranim.setduration; Coloranim.setevaluator (new Argbevaluator ()); Coloranim.setrepeatcount (valueanimator.infinite); Coloranim.setrepeatmode ( Valueanimator.reverse); Coloranim.start ();} @SuppressLint ("Newapi") @Overridepublic boolean ontouchevent (Motionevent event) {if (event.getaction ()! = motionevent.action_down&& Event.getaction ()! = Motionevent.action_move) {return false;}  Shapeholder Newball = Addball (Event.getx (), Event.gety ())/** bouncing animation with squash and stretch **/float starty = Newball.gety (); Float EndY = GetHeight ()-50f;float h = (float) getheight (); Float eventy = Event.gety (); int duration = (i NT) ($ * ((H-eventy)/h)); Valueanimator Bounceanim = objectanimator.offloat (Newball, "Y", Starty, EndY); bounceanim.setduration (duration); Bounceanim.setinterpolator (New Accelerateinterpolator ()); Valueanimator squashAnim1 = objectanimator.offloat (Newball, "X", Newball.getx (), Newball.getx ()-25f); Squashanim1.setduration (DURATION/4); Squashanim1.setrepeatcount (1); Squashanim1.setrepeatmode ( Valueanimator.reverse); Squashanim1.setinterpolator (new Decelerateinterpolator ()); Valueanimator squashAnim2 = objectanimator.offloat (Newball, "width", newball.getwidth (), newball.getwidth () + 50); Squashanim2.setduration (DURATION/4); Squashanim2.setrepeatcount (1); Squashanim2.setrepeatmode (ValueAnimatoR.reverse); Squashanim2.setinterpolator (new Decelerateinterpolator ()); Valueanimator stretchAnim1 = objectanimator.offloat (Newball, "Y", EndY, EndY + 25f); Stretchanim1.setduration (Duration/ 4); Stretchanim1.setrepeatcount (1); Stretchanim1.setinterpolator (new Decelerateinterpolator ()); Stretchanim1.setrepeatmode (Valueanimator.reverse); Valueanimator stretchAnim2 = objectanimator.offloat (Newball, "height", newball.getheight (), Newball.getheight ()-25); Stretchanim2.setduration (DURATION/4); Stretchanim2.setrepeatcount (1); Stretchanim2.setinterpolator (new Decelerateinterpolator ()); Stretchanim2.setrepeatmode (Valueanimator.reverse); Valueanimator Bouncebackanim = objectanimator.offloat (Newball, "Y", EndY, Starty); Bouncebackanim.setduration ( Duration); Bouncebackanim.setinterpolator (new Decelerateinterpolator ());//Sequence the Down/squash&stretch/up Animationsanimatorset bouncer = new Animatorset (); Bouncer.play (Bounceanim). before (SQUASHANIM1); Bouncer.play ( SQUASHANIM1). with (SQUASHANIM2); bouncer.play(SQUASHANIM1). with (STRETCHANIM1), Bouncer.play (SQUASHANIM1). with (STRETCHANIM2); Bouncer.play (Bouncebackanim). After (stretchAnim2);//Fading animation-remove the ball when the animation is donevalueanimator Fadeanim = Objectanimato R.offloat (Newball, "Alpha", 1f, 0f); fadeanim.setduration (+); Fadeanim.addlistener (new Animatorlisteneradapter () {@ overridepublic void Onanimationend (Animator animation) {Balls.remove (((objectanimator) animation). Gettarget ());}}); /Sequence The animations to play one after the otheranimatorset animatorset = new Animatorset (); Animatorset.play (Boun CER). before (Fadeanim);//Start the Animationanimatorset.start (); return true;} Private Shapeholder Addball (float x, float y) {OvalShape circle = new OvalShape (); Circle.resize (50f, 50f); Shapedrawable drawable = new shapedrawable (circle); Shapeholder Shapeholder = new Shapeholder (drawable); Shapeholder.setx (x-25f); shapeholder.sety (y-25f); int red = (int) (M Ath.random () * 255); int green = (int) (Math.random () * 255); int blue = (int) (Math.random () * 255); int color = 0xff000000 | Red << 16 | Green << 8 | Blue Paint paint = drawable.getpaint (); new//Paint (paint.anti_alias_flag); int darkcolor = 0xff000000 | RED/4 << 16 | GREEN/4 << 8 | BLUE/4; Radialgradient gradient = new Radialgradient (37.5f, 12.5f, 50f,color, Darkcolor, Shader.TileMode.CLAMP); Paint.setshader (gradient); Shapeholder.setpaint (paint); Balls.add (Shapeholder); return shapeholder;} @Overrideprotected void OnDraw (canvas canvas) {for (int i = 0; i < balls.size (); ++i) {Shapeholder Shapeholder = balls. Get (i); Canvas.save (); Canvas.translate (Shapeholder.getx (), Shapeholder.gety ()), Shapeholder.getshape (). Draw ( Canvas); Canvas.restore ();}}}

　　

Custom

As follows:

/* Copyright (C) The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License") ; * You are not a use this file except in compliance with the License. * Obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * unless required by appli Cable law or agreed into writing, software * Distributed under the License is distributed on a "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 Com.edaixi.tempbak;import Android.graphics.paint;import Android.graphics.radialgradient;import Android.graphics.drawable.shapedrawable;import android.graphics.drawable.shapes.shape;/** * A data structure that Holds a shape and various properties that can being used to define * how the shape is drawn.    */public class Shapeholder {private float x = 0, y = 0; Private Shapedrawable ShaPe    private int color;    Private radialgradient gradient;    Private float alpha = 1f;    private paint paint;    public void Setpaint (paint value) {paint = value;    } Public Paint Getpaint () {return paint;    } public void SetX (float value) {x = value;    } public float GetX () {return x;    } public void Sety (float value) {y = value;    } public float GetY () {return y;    } public void Setshape (shapedrawable value) {shape = value;    } public shapedrawable Getshape () {return shape;    } public int GetColor () {return color;        } public void SetColor (int value) {shape.getpaint (). SetColor (value);    color = value;    } public void Setgradient (radialgradient value) {gradient = value;    } public radialgradient Getgradient () {return gradient;        } public void Setalpha (float alpha) {this.alpha = Alpha; Shape.setalpha ((int) ((Alpha * 255f) +. 5f));    } public float getwidth () {return Shape.getshape (). GetWidth ();        } public void SetWidth (float width) {Shape s = shape.getshape ();    S.resize (width, s.getheight ());    } public float GetHeight () {return Shape.getshape (). GetHeight ();        } public void SetHeight (float height) {Shape s = shape.getshape ();    S.resize (S.getwidth (), height);    } public Shapeholder (shapedrawable s) {shape = s; }}

　　

The custom layout layout gradient background is as follows:

Package Com.edaixi.tempbak;import Android.animation.argbevaluator;import Android.animation.objectanimator;import Android.animation.valueanimator;import Android.annotation.suppresslint;import Android.content.Context;import Android.util.attributeset;import android.widget.RelativeLayout; @SuppressLint ("Newapi") public class Customerrelativelayout extends Relativelayout {private static final int RED = 0xffff8080;private static final int BLUE = 0 Xff8080ff;public Customerrelativelayout (Context context) {super (context); SETBG ();} Public Customerrelativelayout (context context, AttributeSet attrs,int defstyleattr, int defstyleres) {Super (context, Attrs, Defstyleattr, defstyleres); SETBG ();} Public Customerrelativelayout (context context, AttributeSet Attrs,int defstyleattr) {Super (context, attrs, DEFSTYLEATTR); SETBG ();} Public Customerrelativelayout (context context, AttributeSet Attrs) {Super (context, attrs); SETBG ();} public void Setbg () {Valueanimator Coloranim = Objectanimator.ofint (This, "BACKGROUNDCOlor ", RED, BLUE); coloranim.setduration (+); Coloranim.setevaluator (new Argbevaluator ()); Coloranim.setrepeatcount (Valueanimator.infinite); Coloranim.setrepeatmode (Valueanimator.reverse); Coloranim.start ();}}

　　

A reference in the layout can "

<?xml version= "1.0" encoding= "Utf-8"? ><com.edaixi.tempbak.customerrelativelayout xmlns:android= "/http Schemas.android.com/apk/res/android "    android:id=" @+id/rl_container "    android:layout_width=" match_parent "    android:layout_height=" match_parent "    android:orientation=" vertical "></ Com.edaixi.tempbak.customerrelativelayout>

　　

Android uses property animations to customize the gradient background of a view