I have a gear image which I want to continuously rotate about a fixed point.
Earlier I was accomplishing this by including the image in my Android class as an ImageView and applying a RotateAnimation to it.
#InjectView(R.id.gear00) ImageView gear00;
RotateAnimation ra07 = new RotateAnimation(0, 359, 129, 186);
ra07.setDuration(10000);
ra07.setRepeatCount(RotateAnimation.INFINITE);
ra07.setInterpolator(new LinearInterpolator());
gear00.setAnimation(ra07);
Basically, I was injecting the ImageView into the class and applying a rotation animation.
However, I dont have the luxury of using an ImageView anymore. I have to use a Bitmap and rotate it on the canvas.
How can I go about accomplishing what I was doing earlier in the onDraw() method with a bitmap rotating about a fixed point continiously on the canvas?
Edit1:
I tried one of the suggestions mentioned below my code looks a little like the following
in onCreate():
Matrix matrix = new Matrix();
matrix.setRotate(10, 100, 200);
Then in onDraw() (where gear00Scaled is a bitmap to be rotated on the canvas):
canvas.drawBitmap(gear00Scaled, matrix, new Paint());
Another method I tried involved saving the canvas, rotating it, then restoring it:
canvas.save();
canvas.rotate(10);
canvas.drawBitmap(gear00Scaled, 100, 200, null);
canvas.restore();
Neither seem to be working though!
Make an XML class (suppose: rotate.xml) and place it in res/anim folder and then write the following code in it:
<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="0"
android:interpolator="#android:anim/linear_interpolator"
android:pivotX="50%"
android:pivotY="50%"
android:repeatCount="infinite"
android:toDegrees="360" />
Then in your java class, do the following in OnCreate:
final Animation a = AnimationUtils.loadAnimation(CustomActivity.this,
R.anim.rotate);
a.setDuration(3000);
gear00.startAnimation(a);
OR
To do it using bitmap, I hope the following sequence of code helps you:
Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, targetHeight, config);
Canvas canvas = new Canvas(targetBitmap);
Matrix matrix = new Matrix();
matrix.setRotate(mRotation,source.getWidth()/2,source.getHeight()/2);
canvas.drawBitmap(source, matrix, new Paint());
If you check the following method from:
~frameworks\base\graphics\java\android\graphics\Bitmap.java
public static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height,
Matrix m, boolean filter)
this would explain what it does with rotation and translate.
I want to rotate a custom image as progress dialog in my application. You can use the code below to rotate an image:
RotateAnimation anim = new RotateAnimation(0.0f, 360.0f ,
Animation.RELATIVE_TO_SELF, .5f, Animation.RELATIVE_TO_SELF, .5f);
anim.setInterpolator(new LinearInterpolator());
anim.setRepeatCount(Animation.INFINITE);
anim.setDuration(1000);
imageView.setAnimation(anim);
imageView.startAnimation(anim);
In your onCreate() do
Matrix matrix = new Matrix();
And in onDraw
float angle = (float) (System.currentTimeMillis() % ROTATE_TIME_MILLIS)
/ ROTATE_TIME_MILLIS * 360;
matrix.reset();
matrix.postTranslate(-source.getWidth() / 2, -source.getHeight() / 2);
matrix.postRotate(angle);
matrix.postTranslate(centerX, centerY)
canvas.drawBitmap(source, matrix, null);
invalidate(); // Cause a re-draw
ROTATE_TIME_MILLIS is the full circle time, e.g. 2000 is 2 seconds.
Two things before the code:
You can't use imageview at all at all? Cause you could link it to a canvas and use a bitmap, but it is still an imageview.
I believe the main issue you are having is the other answer is not animating it and you are missing the call to invalidate() the view and redraw it as rotated.
So there are two approaches:
1st is with the imageview, personally I think it is easier and nicer. Below is a method in my activity class and mLittleChef is an ImageView.
public void doCanvas(){
//Create our resources
Bitmap bitmap = Bitmap.createBitmap(mLittleChef.getWidth(), mLittleChef.getHeight(), Bitmap.Config.ARGB_8888);
final Canvas canvas = new Canvas(bitmap);
final Bitmap chefBitmap = BitmapFactory.decodeResource(getResources(),R.drawable.dish_special);
//Link the canvas to our ImageView
mLittleChef.setImageBitmap(bitmap);
ValueAnimator animation= ValueAnimator.ofFloat(0, 359, 129, 186);
animation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator animation) {
float value = (Float) animation.getAnimatedValue();
//Clear the canvas
canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
canvas.save();
canvas.rotate(value, canvas.getWidth()/2, canvas.getHeight()/2);
canvas.drawBitmap(chefBitmap, 0, 0, null);
canvas.restore();
mLittleChef.invalidate();
}
});
animation.setInterpolator(new LinearInterpolator());
animation.setDuration(1000);
animation.start();
}
The other way to do it is with a custom canvas class. Instead of an ImageView, I create my own custom view class for ExampleDrawView mLittleChefDraw; in my layout. You will probably have to monkey with this one a bit to get exactly what you are looking for in terms of rotation, I made it just do a 360 degree turn using the middle of the canvas as the pivot point.
public class ExampleDrawView extends View {
Bitmap bitmap;
Float mRotate= 0f;
Handler h;
//State variables
final int STATE_PAUSE = 2;
final int STATE_ROTATE = 3;
int STATE_CURRENT;
public ExampleDrawView(Context context, AttributeSet attrs) {
super(context, attrs);
h = new Handler();
bitmap= BitmapFactory.decodeResource(getResources(), R.drawable.dish_special);
STATE_CURRENT= STATE_PAUSE;
}
Runnable move = new Runnable() {
#Override
public void run() {
switch (STATE_CURRENT){
case STATE_ROTATE:
if (mRotate<360){
mRotate++;
invalidate();
}else{
STATE_CURRENT= STATE_PAUSE;
}
h.postDelayed(move, 20);
break;
}
}
};
public void startDrawing(){
if(STATE_CURRENT == STATE_PAUSE){
STATE_CURRENT= STATE_ROTATE;
mRotate=(float) 0;
h.postDelayed(move, 20);
}
}
#Override
protected void onDraw(Canvas canvas){
super.onDraw(canvas);
//change your rotate point here, i just made it the middle of the canvas
canvas.rotate(mRotate,getWidth()/2,getHeight()/2);
canvas.drawBitmap(bitmap, 0, 0, null);
}
}
And then back in the activity call this to start it:
public void doCanvasCustomView(){
mLittleChefDraw.startDrawing();
}
Related
I need to create a view that is filled with a dynamic color at runtime. I've accomplished this task however the actual view needs to have a "peak" on the right side. Typically ImageView's are only square or rectangular. Does anyone know how I would accomplish adding a triangular peak to the view?
For example:
You can override the onDraw event of the ImageView and do whatever you need with the canvas object.
public class MyImageView extends ImageView {
...
#Override
public void onDraw(Canvas canvas){
super.onDraw(canvas);
Point[] point = ... //create three points here for the triangle
Paint paint = ... // create your desired color
drawTriangle(canvas, point, paint);
}
And for the triagle draw (see this SO answer):
private void drawTriangle(Canvas canvas, Point[] point, Paint paint) {
float [] points = new float[8];
points[0] = point[0].x;
points[1] = point[0].y;
points[2] = point[1].x;
points[3] = point[1].y;
points[4] = point[2].x;
points[5] = point[2].y;
points[6] = point[0].x;
points[7] = point[0].y;
canvas.drawVertices(VertexMode.TRIANGLES, 8, points, 0, null, 0, null, 0, null, 0, 0, paint);
Path path = new Path();
path.moveTo(point[0].x , point[0].y);
path.lineTo(point[1].x,point[1].y);
path.lineTo(point[2].x,point[2].y);
canvas.drawPath(path,paint);
}
I have created a custom triangle using canvas, I created a class which is as follows:
#SuppressLint("DrawAllocation")
public class GameView extends View {
private Bitmap bmp;
public GameView(Context context) {
super(context);
bmp = BitmapFactory.decodeResource(getResources(), R.drawable.days2);
}
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
Paint paint = new Paint();
paint.setStrokeWidth(4);
paint.setColor(android.graphics.Color.RED);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setAntiAlias(true);
paint.setShadowLayer(4.0f, 0.0f, 2.0f, Color.BLACK);
setLayerType(LAYER_TYPE_SOFTWARE, paint);
Point a = new Point(0, 0);
Point b = new Point(canvas.getWidth(), canvas.getHeight()/2);
Point c = new Point(canvas.getWidth(),0);
Path path = new Path();
path.setFillType(FillType.EVEN_ODD);
path.lineTo(b.x, b.y);
path.lineTo(c.x, c.y);
path.lineTo(a.x, a.y);
path.close();
canvas.drawPath(path, paint);
canvas.rotate(36);
paint.setColor(Color.WHITE);
paint.setTextAlign(Align.CENTER);
paint.setTextSize(50);
canvas.drawText("Vertical 45 degree text", (canvas.getHeight()/2)-30 ,0-30 , paint);
}
}
I want to apply this shape to a listview row, however when I place a view in XML which refers to this class. It takes up my whole layout height. Which I dont want. If i specify a height in dp, the view gets clipped. How to overcome this?
Please dont mind the obect allocation in the onDraw, I will remove this and optimize once I get the thing going.
I want to be able to scale a Rect on android so it fits the whole screen this is my code so far:
public class MainView extends View {
private Main main;
private Rect facebook_rect;
public MainView(Context context){
super(context);
this.main = (Main) context;
setFocusable(true);
setFocusableInTouchMode(true);
}
#Override
protected void onDraw(Canvas canvas){
Paint background = new Paint();
background.setColor(getResources().getColor(R.color.main_background));
canvas.drawRect(0, 0, getWidth(), getHeight(), background);
Paint facebookPaint = new Paint();
facebook_rect = new Rect(0,0,getWidth(),getHeight()/5);
facebookPaint.setColor(getResources().getColor(R.color.facebook_color));
canvas.drawRect(facebook_rect,facebookPaint);
}
#Override
public boolean onTouchEvent(MotionEvent event){
if(event.getAction()!=MotionEvent.ACTION_DOWN)
return super.onTouchEvent(event);
animate("facebook");
return true;
}
private void animate(String string) {
Animation anim = AnimationUtils.loadAnimation(main, R.anim.scale_anim_1stpos);
facebook_rect.startAnimation(anim);
}
}
however this : "facebook_rect.startAnimation(anim);" does not work... any ideas on how to do this?
edit: I also have this as my anim xml file
<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
android:fromYScale="1.0" android:toYScale="3.0"
android:pivotX="0"
android:pivotY="0"
android:interpolator="#android:anim/linear_interpolator"
android:duration="700" android:fillAfter="true" >
</scale>
The effect I'm trying to achieve is something like passbook Apple's new ticket app just in case you have a better idea how to do it. thanks!
If you want to scale something you can use canvas.scale(scaleFactor, scaleFactor);
The first scale factor is the amount you want to scale in X, and the second the amount in Y.
For the animation part take a look at this link, maybe it can help.
First take the sceeen dimensions
DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics );
Next find the scale factor
float scale = displayMetrics.densityDpi;
Next scale the canvas using draw function
canvas.drawRect(left-20*scale, top-20*scale, right+20*scale, bottom, mPaint);
I'm trying to make custom brushes for my Android painting app. I started with Michael's code (found here) and I have managed to get .png brushes and use that as a bitmap and redraw it. It works fine but I can't change the colour. Tried using the setcolorfilter and colormatrixfilter but it doesn't seem to be working. Anyone knows how I can do this?
private Bitmap mBitmapBrush;
private Vector2 mBitmapBrushDimensions;
private List<Vector2> mPositions = new ArrayList<Vector2>(100);
private Paint mPanit;
public MyView(Context c) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapBrush = BitmapFactory.decodeResource(c.getResources(),R.drawable.brush1);
mBitmapBrushDimensions = new Vector2(mBitmapBrush.getWidth(), mBitmapBrush.getHeight());
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(0xFFAAAAAA);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (Vector2 pos : mPositions) {
canvas.drawBitmap(mBitmapBrush, pos.a, pos.b, mPanit);
}
invalidate();
}
When I tried using the Colormatrixfilter, the .set function was giving an error.
I had the same issue. In order to change the bitmap color you need to add color to your paint object and apply it into bitmap. See the working example here,
for (Vector2 pos : customBrushMap.get(p)) {
Paint paint = new Paint();
ColorFilter filter = new PorterDuffColorFilter(R.Color.GREEN, PorterDuff.Mode.SRC_IN);
paint.setColorFilter(filter);
canvas.drawBitmap(mBitmapBrush, pos.x, pos.y, paint);
}
Result,
I am doing a small project for college and wondering if someone can tell me how I would go about doing a scratch card app. This app should have one image overlaying another. The one on top should allow the user to remove the image depending on where they rub on the image and thus part of the image that was removed revealing the image underneath. Pretty much like a scratch card. Any help would be great!
This is the code im using at the moment .
public class workinggraphics extends Activity
{
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//setContentView(R.layout.main);
setContentView(new Panel(this));
LinearLayout l1 = (LinearLayout) findViewById(R.id.LAYOUTTEST1);
Panel p1 = new Panel(null);
}
class Panel extends View{
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mPaint;
// private Paint nPaint;
Bitmap bitmap;
Canvas pcanvas ;
int x = 0;
int y =0;
int r =0;
public Panel(Context context) {
super(context);
Log.v("Panel", "STROKE");
setFocusable(true);
setBackgroundColor(Color.TRANSPARENT);
/*
WallpaperManager wallpaperManager = WallpaperManager.getInstance(context);
//WallpaperDrawable wallpaperDrawable=wallpaperManager.getDrawable();
try {
wallpaperManager.setBitmap(bmp);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
//setBackgroundDrawable(bmp);
// setting paint
/* nPaint = new Paint();
nPaint.setStyle(Paint.Style.FILL);*/
mPaint = new Paint();
mPaint.setAlpha(0);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeCap(Paint.Cap.BUTT);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));//.Mode.DST_IN));
mPaint.setAntiAlias(false);
// getting image from resources
Resources r = this.getContext().getResources();
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.mainscreen_background);
Bitmap bm1 = BitmapFactory.decodeResource(getResources(),R.drawable.foreground_image);
// converting image bitmap into mutable bitmap
bitmap = bm.createBitmap(bm.getWidth(), bm.getHeight(), Config.ARGB_8888);
//bitmap = bm1.createBitmap(bm1.getWidth(),bm1.getHeight(),Config.ARGB_8888);
pcanvas = new Canvas();
pcanvas.setBitmap(bitmap); // drawXY will result on that Bitmap
pcanvas.drawBitmap(bm, 0, 0, null);
pcanvas.drawBitmap(bm1,0,0,null);
}
#Override
protected void onDraw(Canvas canvas) {
Rect cBK = new Rect();
//canvas.set
cBK.set(0,0,canvas.getWidth(),canvas.getHeight());
//pcanvas.drawRect(cBK, nPaint);
// draw a circle that is erasing bitmap
pcanvas.drawCircle(x, y, r, mPaint);
//pcanvas.drawLine(x, y, 0, 0, mPaint);
canvas.drawBitmap(bitmap, 0, 0,null);
super.onDraw(canvas);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// set paramete to draw circle on touch event
x = (int) event.getX();
y = (int) event.getY();
r =20;
// Atlast invalidate canvas
invalidate();
return true;
}
}
}
Now as you can see above there is a lot of comments for things we have tried. Ideally I would like to be able to create an instance of the Panel class, set the workinggraphics class contextview to a XML LinearLayout (OR SurfaceView w/e would be used I dont really know), and then just set a background image on the defined LinearLayout in XML to be revealed when the canvas erases the bitmap image we have set.
Anyway any suggestions would be appricated thanks alot in advanced!
I created a library call WScrarchView where you can implement scratch view just few lines in layout xml. Hope this can help those who still looking for the solution https://github.com/winsontan520/Android-WScratchView