Develop Reference

How to create scratch card which allows user to scratch only once

This code is working, I created Scratch image view through which I can scratch the image view to see the the image, but scratch image view is automatically filling with scratch pattern when I reopen the app or I move to previous activity.only once the user should scratch the image view to view image and it should not fill again when I reopen the app or move to previous activity .Can anyone help me
<com.example.swapnanadendla.scratch.ScratchImageView
android:id="#+id/sample_image"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_gravity="center"
android:layout_marginTop="20dp"
android:background="#android:color/white"
android:src="#drawable/image" />
.
public class ScratchImageView extends ImageView{
public interface IRevealListener {
void onRevealed(ScratchImageView iv);
void onRevealPercentChangedListener(ScratchImageView siv, float percent);
}
public static final float STROKE_WIDTH = 12f;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
/**
* Bitmap holding the scratch region.
*/
private Bitmap mScratchBitmap;
/**
* Drawable canvas area through which the scratchable area is drawn.
*/
private Canvas mCanvas;
/**
* Path holding the erasing path done by the user.
*/
private Path mErasePath;
/**
* Path to indicate where the user have touched.
*/
private Path mTouchPath;
/**
* Paint properties for drawing the scratch area.
*/
private Paint mBitmapPaint;
/**
* Paint properties for erasing the scratch region.
*/
private Paint mErasePaint;
/**
* Gradient paint properties that lies as a background for scratch region.
*/
private Paint mGradientBgPaint;
/**
* Sample Drawable bitmap having the scratch pattern.
*/
private BitmapDrawable mDrawable;
/**
* Listener object callback reference to send back the callback when the image has been revealed.
*/
private IRevealListener mRevealListener;
/**
* Reveal percent value.
*/
private float mRevealPercent;
/**
* Thread Count
*/
private int mThreadCount = 0;
public ScratchImageView(Context context) {
super(context);
init();
}
public ScratchImageView(Context context, AttributeSet set) {
super(context, set);
init();
}
public ScratchImageView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
/**
* Set the strokes width based on the parameter multiplier.
* #param multiplier can be 1,2,3 and so on to set the stroke width of the paint.
*/
public void setStrokeWidth(int multiplier) {
mErasePaint.setStrokeWidth(multiplier * STROKE_WIDTH);
}
/**
* Initialises the paint drawing elements.
*/
private void init() {
mTouchPath = new Path();
mErasePaint = new Paint();
mErasePaint.setAntiAlias(true);
mErasePaint.setDither(true);
mErasePaint.setColor(0xFFFF0000);
mErasePaint.setStyle(Paint.Style.STROKE);
mErasePaint.setStrokeJoin(Paint.Join.BEVEL);
mErasePaint.setStrokeCap(Paint.Cap.ROUND);
setStrokeWidth(6);
mGradientBgPaint = new Paint();
mErasePath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
Bitmap scratchBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_scratch_pattern);
mDrawable = new BitmapDrawable(getResources(), scratchBitmap);
mDrawable.setTileModeXY(Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
setEraserMode();
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mScratchBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mScratchBitmap);
Rect rect = new Rect(0, 0, mScratchBitmap.getWidth(), mScratchBitmap.getHeight());
mDrawable.setBounds(rect);
int startGradientColor = ContextCompat.getColor(getContext(), R.color.scratch_start_gradient);
int endGradientColor = ContextCompat.getColor(getContext(), R.color.scratch_end_gradient);
mGradientBgPaint.setShader(new LinearGradient(0, 0, 0, getHeight(), startGradientColor, endGradientColor, Shader.TileMode.MIRROR));
mCanvas.drawRect(rect, mGradientBgPaint);
mDrawable.draw(mCanvas);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mScratchBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mErasePath, mErasePaint);
}
private void touch_start(float x, float y) {
mErasePath.reset();
mErasePath.moveTo(x, y);
mX = x;
mY = y;
}
/**
* clears the scratch area to reveal the hidden image.
*/
public void clear() {
int[] bounds = getImageBounds();
int left = bounds[0];
int top = bounds[1];
int right = bounds[2];
int bottom = bounds[3];
int width = right - left;
int height = bottom - top;
int centerX = left + width / 2;
int centerY = top + height / 2;
left = centerX - width / 2;
top = centerY - height / 2;
right = left + width;
bottom = top + height;
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
mCanvas.drawRect(left, top, right, bottom, paint);
checkRevealed();
invalidate();
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mErasePath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
drawPath();
}
mTouchPath.reset();
mTouchPath.addCircle(mX, mY, 30, Path.Direction.CW);
}
private void drawPath() {
mErasePath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mErasePath, mErasePaint);
// kill this so we don't double draw
mTouchPath.reset();
mErasePath.reset();
mErasePath.moveTo(mX, mY);
checkRevealed();
//reveal();
}
public void reveal() {
clear();
}
private void touch_up() {
drawPath();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
default:
break;
}
return true;
}
public int getColor() {
return mErasePaint.getColor();
}
public Paint getErasePaint() {
return mErasePaint;
}
public void setEraserMode() {
getErasePaint().setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
}
public void setRevealListener(IRevealListener listener) {
this.mRevealListener = listener;
}
public boolean isRevealed() {
return mRevealPercent == 1;
}
private void checkRevealed() {
if(! isRevealed() && mRevealListener != null) {
int[] bounds = getImageBounds();
int left = bounds[0];
int top = bounds[1];
int width = bounds[2] - left;
int height = bounds[3] - top;
// Do not create multiple calls to compare.
if(mThreadCount > 1) {
Log.d("Captcha", "Count greater than 1");
return;
}
mThreadCount++;
// new AsyncTask<Integer, Void, Float>() {
//
// #Override
// protected Float doInBackground(Integer... params) {
//
// try {
// int left = params[0];
// int top = params[1];
// int width = params[2];
// int height = params[3];
//
// Bitmap croppedBitmap = Bitmap.createBitmap(mScratchBitmap, left, top, width, height);
//
// return BitmapUtils.getTransparentPixelPercent(croppedBitmap);
// } finally {
// mThreadCount--;
// }
// }
//
// public void onPostExecute(Float percentRevealed) {
//
// // check if not revealed before.
// if( ! isRevealed()) {
//
// float oldValue = mRevealPercent;
// mRevealPercent = percentRevealed;
//
// if(oldValue != percentRevealed) {
// mRevealListener.onRevealPercentChangedListener(ScratchImageView.this, percentRevealed);
// }
//
// // if now revealed.
// if( isRevealed()) {
// mRevealListener.onRevealed(ScratchImageView.this);
// }
// }
// }
//
// }.execute(left, top, width, height);
}
}
public int[] getImageBounds() {
int paddingLeft = getPaddingLeft();
int paddingTop = getPaddingTop();
int paddingRight = getPaddingRight();
int paddingBottom = getPaddingBottom();
int vwidth = getWidth() - paddingLeft - paddingRight;
int vheight = getHeight() - paddingBottom - paddingTop;
int centerX = vwidth/2;
int centerY = vheight/2;
Drawable drawable = getDrawable();
Rect bounds = drawable.getBounds();
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
if(width <= 0) {
width = bounds.right - bounds.left;
}
if(height <= 0) {
height = bounds.bottom - bounds.top;
}
int left;
int top;
if(height > vheight) {
height = vheight;
}
if(width > vwidth) {
width = vwidth;
}
ScaleType scaleType = getScaleType();
switch (scaleType) {
case FIT_START:
left = paddingLeft;
top = centerY - height / 2;
break;
case FIT_END:
left = vwidth - paddingRight - width;
top = centerY - height / 2;
break;
case CENTER:
left = centerX - width / 2;
top = centerY - height / 2;
break;
default:
left = paddingLeft;
top = paddingTop;
width = vwidth;
height = vheight;
break;
}
return new int[] {left, top, left + width, top + height};
}
}

What you can do is store into Firebase a variable like isScratched = 1 or 0, if it's 1 it's because the user didn't scratch it yet. If the user scratch it that variable will be 0 and then in onStart you put a listener of Firebase database, if the listener finds out the value is 0 the scratch card will not be available.
I will show you some snippet here
private DatabaseReference mDatabase; //First declare your database reference
Then in init() or onCreate()
mDatabase = FirebaseDatabase.getInstance().getReference();
mDatabase.child("isScratched").setValue("1"); //here we create the isScratched and set it to 1 , meaning that the photo is not even scratched yet
Now, after the photo is scratched just set that value to 0
//After your scratch method or when the user finishes scratching the pick
mDatabase.child("isScratched").setValue("0");
Now in your onStart() or in the Activity where the image appears just attach a listener
mDatabase.child("isScratched").addSingleValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String getScratchedValue = datasnapshot.getValue(String.class);
Log.e("IsScratched : " ,""+getScratchedValue);
if(getScratchedValue.equals(0)){
//Your picture is already scratched, run the method that will show it scratched
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
System.out.println("Database Error: "+databaseError.getDetails());
}
});

Get Touch Coordinates Relative To A Custom ImageView

I implemented custom ImageView. Because my image is large I'm using ScrollView and HorizontalScrollView to scrolling image. I want to draw circle in onTouch event, but its not work in all cases. When I scroll image and fire touch event the x,y coordinates apply to current visible sector of image ( in top right corner its e.g. 0x0, but when I scroll somwhere and in visible top corner it will be 0x0 too), but circle is drawing according to image size.
Another problem is that app could be used on various screen size.
I know that it xamarin c# but in native Android it should be the same. Anyone knows how to draw/get coordinates properly?
public class DrawViewInside : ImageView
{
public static Bitmap bitmapInside;
private Paint paint = new Paint();
private Point point = new Point();
private Canvas mCanvas;
private static Bitmap mutableBitmap;
private Context mContext;
public static Bitmap b;
public void SetCarId(int id)
{
carId = id;
}
public DrawViewInside(Context context, IAttributeSet attrs) : base(context, attrs)
{
mContext = context;
setDefault(drawable);
}
public void SetBitmap(int drawableId)
{
setDefault(drawableId);
Invalidate();
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
int width = MeasureSpec.GetSize(widthMeasureSpec);
int height = width;
var metrics = Resources.DisplayMetrics;
if (b != null)
{
SetMeasuredDimension(b.Width, b.Height);
}
}
public async void setDefault(int drawableId)
{
BitmapFactory.Options options = await GetBitmapOptionsOfImage(drawableId);
paint.Color = Color.Red;
paint.StrokeWidth = 15;
paint.SetStyle(Paint.Style.Stroke);
var metrics = Resources.DisplayMetrics;
var widthInDp = ConvertPixelsToDp(metrics.WidthPixels);
var heightInDp = ConvertPixelsToDp(metrics.HeightPixels);
b = BitmapFactory.DecodeResource(Resources, drawableId);esources, drawableId);
mutableBitmap = b.Copy(Bitmap.Config.Argb8888, true);
mCanvas = new Canvas(mutableBitmap);
mCanvas.Save();
}
protected override void OnDraw(Canvas canvas)
{
DrawCircle(canvas);
}
private void DrawCircle(Canvas canvas)
{
if (mCanvas == null)
{
setDefault(drawable);
}
else
{
mCanvas.Restore();
mCanvas.DrawCircle(point.x, point.y, 10, paint);
mCanvas.Save();
canvas.DrawBitmap(mutableBitmap, 0, 0, paint);
bitmapInside = mutableBitmap;
}
}
public override bool OnTouchEvent(MotionEvent e)
{
switch (e.Action)
{
case MotionEventActions.Down:
break;
case MotionEventActions.Up:
Activity act = (Activity)mContext;
float viewX = e.RawX - this.Left;
float viewY = e.RawY - this.Top;
point.x = viewX;// e.RawX;
point.y = viewY;// e.RawY;
break;
}
Invalidate();
return true;
}
}
public class Point
{
public float x, y;
}

I found solution. Just replace
float viewX = e.RawX - this.Left;
float viewY = e.RawY - this.Top;
point.x = viewX;// e.RawX;
point.y = viewY;// e.RawY;
with
float viewX = e.RawX;// - this.Left;
float viewY = e.RawY;// - this.Top;
int[] viewCoords = new int[2];
this.GetLocationOnScreen(viewCoords);
point.x = viewX - viewCoords[0];// e.RawX;
point.y = viewY - viewCoords[1];// e.RawY;

Customize a ProgressBar to become a Thermometer

How to customize a ProgressBar to look like a Thermometer ? with the possibility to change color.
My suggestion was to rotate the progressBar 90° to become vertical then have it overlay an image of an empty Thermometer but it's bad and messy solution.
I Think the best will be to either to extends View or ProgressBar class and customize the draw method but I have no idea how to draw Thermometer, any Help would be appreciated.

I created something like this for a project
package com.janslab.thermometer.widgets;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.Scroller;
import com.janslab.thermometer.R;
public class DummyThermometer extends View {
private Paint mInnerCirclePaint;
private Paint mOuterCirclePaint;
private Paint mFirstOuterCirclePaint;
//thermometer arc paint
private Paint mFirstOuterArcPaint;
//thermometer lines paints
private Paint mInnerLinePaint;
private Paint mOuterLinePaint;
private Paint mFirstOuterLinePaint;
//thermometer radii
private int mOuterRadius;
private int mInnerRadius;
private int mFirstOuterRadius;
//thermometer colors
private int mThermometerColor = Color.rgb(200, 115, 205);
//circles and lines variables
private float mLastCellWidth;
private int mStageHeight;
private float mCellWidth;
private float mStartCenterY; //center of first cell
private float mEndCenterY; //center of last cell
private float mStageCenterX;
private float mXOffset;
private float mYOffset;
// I 1st Cell I 2nd Cell I 3rd Cell I
private static final int NUMBER_OF_CELLS = 3; //three cells in all ie.stageHeight divided into 3 equal cells
//animation variables
private float mIncrementalTempValue;
private boolean mIsAnimating;
private Animator mAnimator;
public DummyThermometer(Context context) {
this(context, null);
}
public DummyThermometer(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public DummyThermometer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
if (attrs != null) {
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Thermometer, defStyle, 0);
mThermometerColor = a.getColor(R.styleable.Thermometer_therm_color, mThermometerColor);
a.recycle();
}
init();
}
private void init() {
mInnerCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mInnerCirclePaint.setColor(mThermometerColor);
mInnerCirclePaint.setStyle(Paint.Style.FILL);
mInnerCirclePaint.setStrokeWidth(17f);
mOuterCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mOuterCirclePaint.setColor(Color.WHITE);
mOuterCirclePaint.setStyle(Paint.Style.FILL);
mOuterCirclePaint.setStrokeWidth(32f);
mFirstOuterCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mFirstOuterCirclePaint.setColor(mThermometerColor);
mFirstOuterCirclePaint.setStyle(Paint.Style.FILL);
mFirstOuterCirclePaint.setStrokeWidth(60f);
mFirstOuterArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mFirstOuterArcPaint.setColor(mThermometerColor);
mFirstOuterArcPaint.setStyle(Paint.Style.STROKE);
mFirstOuterArcPaint.setStrokeWidth(30f);
mInnerLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mInnerLinePaint.setColor(mThermometerColor);
mInnerLinePaint.setStyle(Paint.Style.FILL);
mInnerLinePaint.setStrokeWidth(17f);
mOuterLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mOuterLinePaint.setColor(Color.WHITE);
mOuterLinePaint.setStyle(Paint.Style.FILL);
mFirstOuterLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mFirstOuterLinePaint.setColor(mThermometerColor);
mFirstOuterLinePaint.setStyle(Paint.Style.FILL);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mStageCenterX = getWidth() / 2;
mStageHeight = getHeight();
mCellWidth = mStageHeight / NUMBER_OF_CELLS;
//center of first cell
mStartCenterY = mCellWidth / 2;
//move to 3rd cell
mLastCellWidth = (NUMBER_OF_CELLS * mCellWidth);
//center of last(3rd) cell
mEndCenterY = mLastCellWidth - (mCellWidth / 2);
// mOuterRadius is 1/4 of mCellWidth
mOuterRadius = (int) (0.25 * mCellWidth);
mInnerRadius = (int) (0.656 * mOuterRadius);
mFirstOuterRadius = (int) (1.344 * mOuterRadius);
mFirstOuterLinePaint.setStrokeWidth(mFirstOuterRadius);
mOuterLinePaint.setStrokeWidth(mFirstOuterRadius / 2);
mFirstOuterArcPaint.setStrokeWidth(mFirstOuterRadius / 4);
mXOffset = mFirstOuterRadius / 4;
mXOffset = mXOffset / 2;
//get the d/f btn firstOuterLine and innerAnimatedline
mYOffset = (mStartCenterY + (float) 0.875 * mOuterRadius) - (mStartCenterY + mInnerRadius);
mYOffset = mYOffset / 2;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
drawFirstOuterCircle(canvas);
drawOuterCircle(canvas);
drawInnerCircle(canvas);
drawFirstOuterLine(canvas);
drawOuterLine(canvas);
animateInnerLine(canvas);
drawFirstOuterCornerArc(canvas);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//take care of paddingTop and paddingBottom
int paddingY = getPaddingBottom() + getPaddingTop();
//get height and width
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
height += paddingY;
setMeasuredDimension(width, height);
}
private void drawInnerCircle(Canvas canvas) {
drawCircle(canvas, mInnerRadius, mInnerCirclePaint);
}
private void drawOuterCircle(Canvas canvas) {
drawCircle(canvas, mOuterRadius, mOuterCirclePaint);
}
private void drawFirstOuterCircle(Canvas canvas) {
drawCircle(canvas, mFirstOuterRadius, mFirstOuterCirclePaint);
}
private void drawCircle(Canvas canvas, float radius, Paint paint) {
canvas.drawCircle(mStageCenterX, mEndCenterY, radius, paint);
}
private void drawOuterLine(Canvas canvas) {
float startY = mEndCenterY - (float) (0.875 * mOuterRadius);
float stopY = mStartCenterY + (float) (0.875 * mOuterRadius);
drawLine(canvas, startY, stopY, mOuterLinePaint);
}
private void drawFirstOuterLine(Canvas canvas) {
float startY = mEndCenterY - (float) (0.875 * mFirstOuterRadius);
float stopY = mStartCenterY + (float) (0.875 * mOuterRadius);
drawLine(canvas, startY, stopY, mFirstOuterLinePaint);
}
private void drawLine(Canvas canvas, float startY, float stopY, Paint paint) {
canvas.drawLine(mStageCenterX, startY, mStageCenterX, stopY, paint);
}
//simulate temperature measurement for now
private void animateInnerLine(Canvas canvas) {
if (mAnimator == null)
measureTemperature();
if (!mIsAnimating) {
mIncrementalTempValue = mEndCenterY + (float) (0.875 * mInnerRadius);
mIsAnimating = true;
} else {
mIncrementalTempValue = mEndCenterY + (float) (0.875 * mInnerRadius) - mIncrementalTempValue;
}
if (mIncrementalTempValue > mStartCenterY + mInnerRadius) {
float startY = mEndCenterY + (float) (0.875 * mInnerRadius);
drawLine(canvas, startY, mIncrementalTempValue, mInnerCirclePaint);
} else {
float startY = mEndCenterY + (float) (0.875 * mInnerRadius);
float stopY = mStartCenterY + mInnerRadius;
drawLine(canvas, startY, stopY, mInnerCirclePaint);
mIsAnimating = false;
stopMeasurement();
}
}
private void drawFirstOuterCornerArc(Canvas canvas) {
float y = mStartCenterY - (float) (0.875 * mFirstOuterRadius);
RectF rectF = new RectF(mStageCenterX - mFirstOuterRadius / 2 + mXOffset, y + mFirstOuterRadius, mStageCenterX + mFirstOuterRadius / 2 - mXOffset, y + (2 * mFirstOuterRadius) + mYOffset);
canvas.drawArc(rectF, -180, 180, false, mFirstOuterArcPaint);
}
public void setThermometerColor(int thermometerColor) {
this.mThermometerColor = thermometerColor;
mInnerCirclePaint.setColor(mThermometerColor);
mFirstOuterCirclePaint.setColor(mThermometerColor);
mFirstOuterArcPaint.setColor(mThermometerColor);
mInnerLinePaint.setColor(mThermometerColor);
mFirstOuterLinePaint.setColor(mThermometerColor);
invalidate();
}
//simulate temperature measurement for now
private void measureTemperature() {
mAnimator = new Animator();
mAnimator.start();
}
private class Animator implements Runnable {
private Scroller mScroller;
private final static int ANIM_START_DELAY = 1000;
private final static int ANIM_DURATION = 4000;
private boolean mRestartAnimation = false;
public Animator() {
mScroller = new Scroller(getContext(), new AccelerateDecelerateInterpolator());
}
public void run() {
if (mAnimator != this)
return;
if (mRestartAnimation) {
int startY = (int) (mStartCenterY - (float) (0.875 * mInnerRadius));
int dy = (int) (mEndCenterY + mInnerRadius);
mScroller.startScroll(0, startY, 0, dy, ANIM_DURATION);
mRestartAnimation = false;
}
boolean isScrolling = mScroller.computeScrollOffset();
mIncrementalTempValue = mScroller.getCurrY();
if (isScrolling) {
invalidate();
post(this);
} else {
stop();
}
}
public void start() {
mRestartAnimation = true;
postDelayed(this, ANIM_START_DELAY);
}
public void stop() {
removeCallbacks(this);
mAnimator = null;
}
}
private void stopMeasurement() {
if (mAnimator != null)
mAnimator.stop();
}
#Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
measureTemperature();
}
#Override
protected void onDetachedFromWindow() {
stopMeasurement();
super.onDetachedFromWindow();
}
#Override
public void setVisibility(int visibility) {
super.setVisibility(visibility);
switch (visibility) {
case View.VISIBLE:
measureTemperature();
break;
default:
stopMeasurement();
break;
}
}
}
attrs.xml file
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="Thermometer">
<attr name="therm_color" format="color" />
</declare-styleable>
</resources>

First I would provide 2 setters, one for color and one for the temperature value, normalized from 0 ... 1, where 0 means no visible bar, and 1 means a fully visible bar.
public void setColor(int color) {
mColor = color;
invalidate(); // important, this triggers onDraw
}
public void setValue(float value) {
mValue = -(value - 1);
invalidate(); // important, this triggers onDraw
}
Notice for value, I reverse the value, since we draw the bar from bottom up, instead from top down. It makes sense in the canvas.drawRect method.
If your CustomView may have custom sizes, set your size of the progressBar (I refer to the inner bar as progressBar) in onSizeChanged, as this gets called when the View has changed it's size.
If it is a fixed size, you can just provide those values statically in an init function or the constructor.
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mProgressRect = new Rect(
/*your bar left offset relative to base bitmap*/,
/*your bar top offset relative to base bitmap*/,
/*your bar total width*/,
/*your max bar height*/
);
}
Then in ondraw, take these values into account and draw accordingly.
First draw the Bitmap, depending on your selected color (I would provide the thermometer base as a Bitmap, as long as it does not have to be completely dynamically drawn (special requirements)
Then draw the progress bar, with an height based on mValue * totalHeight of the bar, using the color provided in the setter.
For example:
#Override
protected void onDraw(Canvas canvas) {
// draw your thermometer base, bitmap based on color value
canvas.drawBitmap( /*your base thermometer bitmap here*/ );
// draw the "progress"
canvas.drawRect(mProgressRect.left, mProgressRect.top + (mValue * mProgressRect.bottom - mProgressRect.top), mProgressRect.right, mProgressRect.bottom, mPaint);
}
Hope that helps.
P.S.:
If you want to have the thermometer base image also dynamically drawn, it's a slightly different story, it would involve creating a path first and draw it with a Paint object, instead of drawing the bitmap.
EDIT:
Even better, if you want a simple solution for the "roundness" of the bar, draw a line instead a rect.
Define a line paint object like this:
mPaint = new Paint();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(20); // thickness of your bar
then in onDraw, instead drawRect:
// draw the "progress"
canvas.drawLine(mProgressRect.left, mProgressRect.top + (mValue * mProgressRect.bottom - mProgressRect.top), mProgressRect.left, mProgressRect.bottom, mPaint);
Be sure to adjust your mProgressRectaccordingly.

Force redraw of custom view (android)

I just have read similar questions but all answer don't work for me.
I have this custom view:
public class CompassTargetView extends View {
Context mContext;
Bitmap mBmp;
Matrix matrix;
int w, h, bw, bh;
int px = -1, py = -1;
public CompassTargetView(Context context, AttributeSet attrs) {
super(context, attrs);
setWillNotDraw(false);
mContext = context;
Resources res = getResources();
mBmp = BitmapFactory.decodeResource(res, R.drawable.ttriangle);
bw = mBmp.getWidth();
bh = mBmp.getHeight();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(px == -1 && py == -1){
px=w/2-bw/2;
py=h/2-bh/2;
}
if (matrix != null) {
canvas.drawBitmap(mBmp, matrix, null);
matrix = null;
} else {
canvas.drawBitmap(mBmp, px, py, null);
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//registriamo le dimensioni della view
w = MeasureSpec.getSize(widthMeasureSpec);
h = MeasureSpec.getSize(heightMeasureSpec);
setMeasuredDimension(w, h);
}
public void setTrinagleIcon(){
Resources res = getResources();
mBmp = BitmapFactory.decodeResource(res, R.drawable.ttriangle);
bw = mBmp.getWidth();
bh = mBmp.getHeight();
invalidate();
}
public void setCircleIcon(){
Resources res = getResources();
mBmp = BitmapFactory.decodeResource(res, R.drawable.tcircle);
bw = mBmp.getWidth();
bh = mBmp.getHeight();
invalidate();
}
public void setXY(Integer nx, Integer ny){
px = nx - bw/2;
py = ny - bh/2;
invalidate();
}
public void translateIcon(Integer nx, Integer ny){
matrix = new Matrix();
matrix.reset();
matrix.postTranslate(nx, ny);
invalidate();
}
public void rotateIcon(Integer nx, Integer ny, Float ang){
matrix = new Matrix();
matrix.reset();
matrix.postRotate(ang, nx, ny);
invalidate();
}
}
it show a small icon then I want use setXY, translateIcon and rotateIcon to "animate" the icon. However the onDraw method is call only on view create after this if I call setXY, translateIcon and rotateIcon onDraw is not call.
I just use invalidate(); and I have try setWillNotDraw(false); but this don't work.
Any idea?

Displaying a Toast in the onDraw is a very bad idea since it may cause a call to onDraw which will display the Toast and it will call onDraw.... infinite loop.
So replace the Toast by log (and keep the log only during debugging since onDraw is call very very often) and see what append.
The problem is that you are not updating the member matrix. You are creating a new one !
public void translateIcon(Integer nx, Integer ny){
Matrix matrix = new Matrix(); // <-- WRONG
matrix = new Matrix(); // <-- CORRECT
...
invalidate();
}

change color when int is changed in other class

I have IndicationBar class that should draw rectangle with logo inside and on int value case change rectangle color. I am new to java and android so im learning everyday.
At this moment the value of int is changing in other class and i call it BluetoothChat.statusSviesos. its public static int. Do i need to create interface Listener or how can i run private void Sviesos() every time int is changed? It runs only once in start.
public class IndicationBar extends View {
private static final String TAG = IndicationBar.class.getSimpleName();
// drawing tools
private RectF Rect;
private Paint rectPaint;
private Paint rimCirclePaint;
private RectF faceRect;
private Bitmap faceTexture;
private Paint facePaint;
private Paint rimShadowPaint;
private Paint titlePaint;
private Path titlePath;
private Paint logoPaint;
private Bitmap logo;
private Matrix logoMatrix;
private float logoScale;
private Paint backgroundPaint;
// end drawing tools
private Bitmap background; // holds the cached static part
public IndicationBar(Context context) {
super(context);
init();
}
public IndicationBar(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public IndicationBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
#Override
protected void onRestoreInstanceState(Parcelable state) {
Bundle bundle = (Bundle) state;
Parcelable superState = bundle.getParcelable("superState");
super.onRestoreInstanceState(superState);
}
private void init() {
initDrawingTools();
}
// private String getTitle() {
// return "DANCER";
// }
private void Sviesos(){
//Rect = new RectF(0.1f, 0.1f, 0.9f, 0.9f);
//rectPaint = new Paint();
//valueSviesos = BluetoothChat.statusSviesos;
switch(BluetoothChat.statusSviesos){
case 0 : rectPaint.setColor(Color.parseColor("#1BA1E2"));
break;
case 1 : rectPaint.setColor(Color.parseColor("#A05000"));
break;
case 2 : rectPaint.setColor(Color.parseColor("#E671B8"));
break;
case 3 : rectPaint.setColor(Color.parseColor("#F09609"));
break;
case 4 : rectPaint.setColor(Color.parseColor("#1BA1E2"));
break;
}
//rectPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
}
private void initDrawingTools() {
Rect = new RectF(0.1f, 0.1f, 0.9f, 0.9f);
rectPaint = new Paint();
rectPaint.setColor(Color.parseColor("#8CBF26"));
rectPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
Sviesos();
rimCirclePaint = new Paint();
rimCirclePaint.setAntiAlias(true);
rimCirclePaint.setStyle(Paint.Style.STROKE);
rimCirclePaint.setColor(Color.argb(0x4f, 0x33, 0x36, 0x33));
rimCirclePaint.setStrokeWidth(0.005f);
float rimSize = 0.02f;
faceRect = new RectF();
faceRect.set(Rect.left + rimSize, Rect.top + rimSize,
Rect.right - rimSize, Rect.bottom - rimSize);
faceTexture = BitmapFactory.decodeResource(getContext().getResources(),
R.drawable.plastic);
BitmapShader paperShader = new BitmapShader(faceTexture,
Shader.TileMode.MIRROR,
Shader.TileMode.MIRROR);
Matrix paperMatrix = new Matrix();
facePaint = new Paint();
facePaint.setFilterBitmap(true);
paperMatrix.setScale(1.0f / faceTexture.getWidth(),
1.0f / faceTexture.getHeight());
paperShader.setLocalMatrix(paperMatrix);
facePaint.setStyle(Paint.Style.FILL);
facePaint.setShader(paperShader);
rimShadowPaint = new Paint();
rimShadowPaint.setShader(new RadialGradient(0.5f, 0.5f, faceRect.width() / 2.0f,
new int[] { 0x00000000, 0x00000500, 0x50000500 },
new float[] { 0.96f, 0.96f, 0.99f },
Shader.TileMode.MIRROR));
rimShadowPaint.setStyle(Paint.Style.FILL);
titlePaint = new Paint();
titlePaint.setColor(Color.parseColor("#1BA1E2"));
titlePaint.setAntiAlias(true);
titlePaint.setTypeface(Typeface.DEFAULT_BOLD);
titlePaint.setTextAlign(Paint.Align.CENTER);
titlePaint.setTextSize(0.09f);
titlePaint.setTextScaleX(0.9f);
titlePath = new Path();
titlePath.addArc(new RectF(0.24f, 0.24f, 0.76f, 0.76f), -180.0f, -180.0f);
logoPaint = new Paint();
logoPaint.setFilterBitmap(true);
logo = BitmapFactory.decodeResource(getContext().getResources(), R.drawable.sviesos);
logoMatrix = new Matrix();
logoScale = (1.0f / logo.getWidth()) * 0.3f;;
logoMatrix.setScale(logoScale, logoScale);
backgroundPaint = new Paint();
backgroundPaint.setFilterBitmap(true);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.d(TAG, "Width spec: " + MeasureSpec.toString(widthMeasureSpec));
Log.d(TAG, "Height spec: " + MeasureSpec.toString(heightMeasureSpec));
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int chosenWidth = chooseDimension(widthMode, widthSize);
int chosenHeight = chooseDimension(heightMode, heightSize);
int chosenDimension = Math.min(chosenWidth, chosenHeight);
setMeasuredDimension(chosenDimension, chosenDimension);
}
private int chooseDimension(int mode, int size) {
if (mode == MeasureSpec.AT_MOST || mode == MeasureSpec.EXACTLY) {
return size;
} else { // (mode == MeasureSpec.UNSPECIFIED)
return getPreferredSize();
}
}
// in case there is no size specified
private int getPreferredSize() {
return 300;
}
private void drawRect(Canvas canvas) {
// first, draw the metallic body
canvas.drawRect(Rect, rectPaint);
// now the outer rim circle
//canvas.drawOval(rimRect, rimCirclePaint);
}
// private void drawFace(Canvas canvas) {
// canvas.drawOval(faceRect, facePaint);
// // draw the inner rim circle
// canvas.drawOval(faceRect, rimCirclePaint);
// // draw the rim shadow inside the face
// canvas.drawOval(faceRect, rimShadowPaint);
// }
private void drawBackground(Canvas canvas) {
if (background == null) {
Log.w(TAG, "Background not created");
} else {
canvas.drawBitmap(background, 0, 0, backgroundPaint);
}
}
#Override
protected void onDraw(Canvas canvas) {
drawBackground(canvas);
float scale = (float) getWidth();
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(scale, scale);
drawLogo(canvas);
canvas.restore();
}
private void drawLogo(Canvas canvas) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.translate(0.5f - logo.getWidth() * logoScale / 2.0f,
0.5f - logo.getHeight() * logoScale / 2.0f);
canvas.drawBitmap(logo, logoMatrix, logoPaint);
canvas.restore();
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
Log.d(TAG, "Size changed to " + w + "x" + h);
regenerateBackground();
}
private void regenerateBackground() {
// free the old bitmap
Sviesos();
if (background != null) {
background.recycle();
}
background = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
Canvas backgroundCanvas = new Canvas(background);
float scale = (float) getWidth();
backgroundCanvas.scale(scale, scale);
drawRect(backgroundCanvas);
}
}

Use the Observer pattern for this. Change the BluetoothChat
public class BluetoothChat {
private static int statusSviesos;
//the list of observers
private static List<Observer> observerList;
//adds an observer to observe statusSciesos
public static void addStatusSviesosObserver(Observer observer) {
observerList.add(observer);
}
//getter function returns the value
public static int getStatusSviesos(){
return statusSviesos;
}
//setter function sets the value and notifies observer
public static void setStatusSviesos(int statusSviesos){
BluetoothChat.statusSviesos=statusSviesos;
for(Observer current: observerList){
current.notifyChange(statusSviesos);
}
}
public static interface Observer {
public void notifyChange(int newStatus);
}
...
Then create an Observer in the IndicationBar and add it to the BluetoothChat:
Observer observer = new Observer() {
#Override
public void notifyChange(int newStatus) {
Sviesos();
}
};
BluetoothChat.addStatusSviesosObserver(observer);
This is a raw implementation of the Observer pattern. There should be a removeObserver-method too and it is not thread-safe. There is a default implementations ready in Java (Observer-class and Observable-class) and there are alternative implementations like PropertyChangeObserver. But for your current use case this should do the job. Also read Wikipedia and Vogellas tutorial
General tips:
Does BluetoothChat's attribute really has to be static? I recommend you to use static as less as possible. Better create an Object once and pass it around instead. You can search for "global state" and why to avoid it for further information.
You could create an array of Colors (or Color-strings like "#F09609") and access it with the int you get to get rid of the switch-statement.
Try to apply code style conventions everywhere, method names and variables should always start with a small letter (except constants which are ALL_BIG) and should be descriptive.