Android 2D Drawing and Animation Framework
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The document discusses Android drawing and animation. It covers drawing using drawables, shapes, and custom views. It also covers view animation, which includes tween animation defined in XML files to transition views between states, and frame animation to transition between drawables. The document also introduces the Android property animation system for animating any object properties.
![Tween
Anima-on:
XML
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@[package:]anim/interpolator_resource"
android:shareInterpolator=["true" | "false"] >
<alpha
android:fromAlpha="float"
android:toAlpha="float" />
<scale
android:fromXScale="float"
android:toXScale="float"
android:fromYScale="float"
android:toYScale="float"
android:pivotX="float"
android:pivotY="float" />
<translate
android:fromXDelta="float"
android:toXDelta="float"
android:fromYDelta="float"
android:toYDelta="float" />
<rotate
android:fromDegrees="float"
android:toDegrees="float"
android:pivotX="float"
android:pivotY="float" />
<set>
...
</set>
</set>](https://image.slidesharecdn.com/06-android-drawing-and-animation-110810020455-phpapp01/85/Android-2D-Drawing-and-Animation-Framework-28-320.jpg)
Android 2D Drawing and Animation Framework
- 1. Android Drawing and Anima-on Jussi Pohjolainen Tampere University of Applied Sciences
- 2. Android Graphics • Custom 2D Graphics – android.graphics.drawable package • OpenGL ES 1.0 high performance 3D graphics – javax.microedition.khronos.opengles package • In this lecture, we will concentrate on the 2D graphics
- 3. DRAWABLES AND SCREEN SIZES
- 4. Drawables • A Drawable is a general abstrac-on for “something that can be drawn” – BitmapDrawable, ShapeDrawable, LayerDrawable … • How to define and instan-ate Drawable? 1. Use image saved to project resources 2. XML file that defines drawable proper-es 3. In Java
- 5. 1. Use image saved to project resources • Supported types: PNG (preferred), JPG (acceptable) and GIF (discoured) • Add the file to res/drawable • Refer using the R – class • Use it from Java or XML
- 6. Save Image to Project
- 7. Screen Sizes • Android supports different screen sizes • Simplifying developer’s work: – 4 generalized sizes: small, normal, large, xlarge – 4 generalized densi-es: ldpi, mdpi, hdpi, xhdpi
- 8. Emulators for different Screen Sizes
- 9. Resources res/layout/my_layout.xml // layout for normal screen size res/layout-small/my_layout.xml // layout for small screen size res/layout-large/my_layout.xml // layout for large screen size res/layout-large-land/my_layout.xml // layout for large screen size in landscape mode res/layout-xlarge/my_layout.xml // layout for extra large screen size res/drawable-lhdpi/my_icon.png // image for low density res/drawable-mdpi/my_icon.png // image for medium density res/drawable-hdpi/my_icon.png // image for high density res/drawable-nodpi/composite.xml // density independent resource
- 10. Displaying Image using Java public class DrawingExamples extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Context mContext = getApplicationContext(); Resources res = mContext.getResources(); Drawable drawable = res.getDrawable(R.drawable.androidlogo); ImageView imageview = new ImageView(this); imageview.setImageDrawable(drawable); setContentView(imageview); } }
- 11. Easier way public class DrawingExamples extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ImageView imageview = new ImageView(this); imageview.setImageResource(R.drawable.androidlogo); setContentView(imageview); } }
- 12. Or use it via the XML <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/ res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent”> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/androidlogo" /> </LinearLayout>
- 13. 2D DRAWING
- 14. Drawing on a View • If no significant frame-‐rate speed needed, draw to custom View • Extend View and define onDraw – method • onDraw() is called automa-cally • Redraw: invalidate() • Inside onDraw(), Canvas is given
- 15. Simple 2D Drawing: View public class CustomDrawableView extends View { public CustomDrawableView(Context context, AttributeSet attr) { super(context, attr); } protected void onDraw(Canvas canvas) { // Paint class holds style information Paint myPaint = new Paint(); myPaint.setStrokeWidth(3); myPaint.setColor(0xFF097286); canvas.drawCircle(200, 200, 50, myPaint); invalidate(); } }
- 16. Simple 2D Drawing: View <fi.tamk.CustomDrawableView android:layout_width="fill_parent" android:layout_height="wrap_content" />
- 17. ShapeDrawable • With ShapeDrawable, one can draw primi-ve 2D shapes – ArcShape, OvalShape, RoundRectShape, PathShape, RectShape • ShapeDrawable takes Shape object and manages it into screen • Shapes can be defined in XML
- 18. Shape Drawable in Java // Drawing primitive 2D shapes public class CustomDrawableView extends View { private ShapeDrawable mDrawable; public CustomDrawableView(Context context) { super(context); int x = 10; int y = 10; int width = 300; int height = 50; mDrawable = new ShapeDrawable(new OvalShape()); mDrawable.getPaint().setColor(0xff74AC23); mDrawable.setBounds(x, y, x + width, y + height); } protected void onDraw(Canvas canvas) { mDrawable.draw(canvas); } }
- 19. Shape Drawable in XML // res/drawable-xxx/myshapes.xml <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <gradient android:angle="90" android:startColor="#ffffff" android:endColor="#ff0000" android:type="linear" /> <size android:width="60dp" android:height="40dp" /> </shape>
- 20. Shape Drawable in XML // res/layout/main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/ android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/myshapes" /> </LinearLayout>
- 21. Result
- 22. ANIMATION
- 23. About Anima-on – 1) View Anima<on • Any View object to perform tweened anima-on and frame by frame anima-on • Tween anima-on calculates anima-on given informa-on: start, end, size, rota-on and other • Frame by frame: series of drawables one ader another – 2) Property Anima<on System (Android 3.x) • “Animate almost anything” • Define anima-on to change any object property over -me, whether in screen or not
- 24. Differences • View + Less -me to setup + Less code to write -‐ Only View objects -‐ Only certain aspects to animate (scaling, rota-ng..) -‐ View itself is not modified when anima-ng • Property anima<on system + Anima-ng also non View objects + Anima-ng any property of any object -‐ More work
- 25. VIEW ANIMATION
- 26. About View Anima-on • View anima-on can be 1) tween or 2) frame by frame anima-on • Tween anima-on – Can perform series of simple transforma-ons (posi-on, size, rota-on, transparency) on View object – In XML or in code • Frame anima-on – Sequence of different images – In XML or in code
- 27. 1) Tween anima-on • Preferred way: Define in XML • Anima-on xml is stored in res/anim directory • Root element can be: alpha, scale, translate, rotate or set that holds groups of these elements
- 28. Tween Anima-on: XML <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:interpolator="@[package:]anim/interpolator_resource" android:shareInterpolator=["true" | "false"] > <alpha android:fromAlpha="float" android:toAlpha="float" /> <scale android:fromXScale="float" android:toXScale="float" android:fromYScale="float" android:toYScale="float" android:pivotX="float" android:pivotY="float" /> <translate android:fromXDelta="float" android:toXDelta="float" android:fromYDelta="float" android:toYDelta="float" /> <rotate android:fromDegrees="float" android:toDegrees="float" android:pivotX="float" android:pivotY="float" /> <set> ... </set> </set>
- 29. Tween Anima-on: Java TextView v = (TextView) findViewById(R.id.textview1); Animation myanimation = AnimationUtils.loadAnimation(this, R.anim.myanimation); v.startAnimation(myanimation);
- 30. Basic Defini-ons • <alpha> – fade-‐in or fade-‐out anima-ons. • <scale> – Resizing anima-on. • <translate> – Ver-cal and or horizontal movement. • <rotate> – A rota-on of an anima-on
- 31. Example of Translate <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:shareInterpolator="false"> <translate android:fromXDelta="0" android:fromYDelta="0" android:toXDelta="0" android:toYDelta="100%p" android:duration="700" android:repeatMode="reverse" android:repeatCount="1" /> </set> Start from 0,0 End to 0, 100% from parent Dura-on is 700 Repeat in reverse one -me
- 33. Scale <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:shareInterpolator="false"> <scale android:fromXScale="1" android:fromYScale="1" android:toXScale="6" android:toYScale="6" android:duration="700" android:repeatMode="reverse" android:repeatCount="1" /> </set>
- 35. Rotate <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:shareInterpolator="false"> <rotate android:fromDegrees="0" android:toDegrees="360" android:pivotX="50%" android:pivotY="50%" android:duration="700" /> </set>
- 37. Alpha <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/ android" android:shareInterpolator="false"> <alpha android:fromAlpha = "1" android:toAlpha = "0" android:duration = "1000" android:repeatMode = "reverse" android:repeatCount= "1" /> </set>
- 39. Using Several Anima-ons <?xml version="1.0" encoding="um-‐8"?> <scale <set xmlns:android="hpp://schemas.android.com/apk/res/ android:fromXScale = "1" android" android:fromYScale = "1" android:shareInterpolator="false"> android:toXScale = "6" <alpha android:toYScale = "6" android:fromAlpha = "1" android:pivotX = "50%" android:toAlpha = "0" android:pivotY = "50%" android:dura-on = "1000" android:duration = "1000" android:repeatMode = "reverse" android:repeatMode = "reverse" android:repeatCount= "1" /> android:repeatCount = "1" /> <rotate </set> android:fromDegrees = "0" android:toDegrees = "360" android:pivotX = "50%" android:pivotY = "50%" android:dura-on = "1000" android:repeatMode = "reverse" android:repeatCount = "1" />
- 41. Interpola-on • Interpola-on is an anima-on modifier defined in xml • Rate of change in anima-on – Accelerate, decelerate, bounce…
- 42. Example of Interpola-on <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android" android:shareInterpolator="true" android:interpolator="@android:anim/bounce_interpolator" > <translate android:fromXDelta="0" android:fromYDelta="0" android:toXDelta="0" android:toYDelta="100%p" android:duration="700" /> </set>
- 45. 2) Frame Anima-on • Create XML file that consists of sequence of different images • Root-‐element: <anima-on-‐list> and series of child elements <item>
- 46. Example <?xml version="1.0" encoding="utf-8"?> <animation-list xmlns:android="http://schemas.android.com/apk/res/ android" android:oneshot="false"> <item android:drawable="@drawable/a1" android:duration="200" /> <item android:drawable="@drawable/a2" android:duration="200" /> <item android:drawable="@drawable/a3" android:duration="200" /> <item android:drawable="@drawable/a4" android:duration="200" /> <item android:drawable="@drawable/a5" android:duration="200" /> <item android:drawable="@drawable/a6" android:duration="200" /> <item android:drawable="@drawable/a7" android:duration="200" /> <item android:drawable="@drawable/a8" android:duration="200" /> </animation-list>
- 47. Star-ng the Frame Anima-on ImageView player = (ImageView) findViewById(R.id.player); player.setImageResource(R.drawable.frameanimation); AnimationDrawable anim = (AnimationDrawable) player.getDrawable(); anim.start();
- 48. Honeycomb Feature! PROPERTY ANIMATION
- 49. Property Anima-on • Extend anima-on beyond Views! – Also limited scope: move, rotate, scale, alpha. That’s it. • With Property Anima-on, you can animate almost anything • Changes the object itself • Anima-ng values over <me
- 50. ValueAnimator • To animate values 0.0 – 1.0 – ValueAnimator anim = ValueAnimator.ofInt(0, 100); – anim.setDuration(500); – anim.start(); • It animates, but nothing can be seen. Add listener! – anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { – public void onAnimationUpdate(ValueAnimator animation) { – int value = (Integer) animation.getAnimatedValue(); – // do something with value... – } – });
- 51. ObjectAnimator: animate objects! MyPoint myobject = new MyPoint(0,0); // Animate myobject’s x-attribute from default value // to 20! ObjectAnimator anim2 = ObjectAnimator.ofInt(myobject, "x", 20); anim2.setDuration(2500); anim2.start(); Assumes that myobject has getX() and setX(int x) methods1
- 52. View class in Honeycomb • In Honeycomb, View class has several set/get methods.. For example – setAlpha (float alpha) – float getAlpha () • So by using Object Animator, you can animate the alpha (transparency) for every view!
- 53. Value/Object Animator Methods • setStartDelay(long) • setRepeatCount(int) • setRepeatMode(int) • setInterPolator(TimeInterpolator)
- 54. Example anima-ng View // Getting reference to TextView defined in xml tv = (TextView) findViewById(R.id.textview1); ObjectAnimator anim = ObjectAnimator.ofFloat(tv, "alpha", 0); anim.setDuration(1000); anim.setRepeatCount(ObjectAnimator.INFINITE); anim.setRepeatMode(ObjectAnimator.REVERSE); anim.start();
- 56. AnimatorSet • Choreograph mul-ple anima-ons • Play several anima-ons together – playTogether(Animator…) • Play anima-ons one ader another – playSequen-ally(Animator…) • Or combina-on of above – with(), before(), ader() methods