I have a class (SpotDetails) which includes a fragment which is drawn programically. Untill now i've had the fragment drawing class (WindRose) as a child of the main class.
What i would like to do is to move the WindRose class into a AsynTask for better User Experience. Now the Application is suffering from too much work on the main thread.
Code to implement the WindRose :
WindRose windRose = new WindRose(SpotDetails.this);
//Add a new windRose (Which is created under)
FrameLayout.addView(windRose);
WindRose code :
public class WindRose extends View {
public WindRose(Context context) {
super(context);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
float height = (float) getHeight();
float width = (float) getWidth();
float radius;
if (width > height) {
radius = height / 2;
} else {
radius = width / 2;
}
// radius = (height )/ 2;
Path path = new Path();
path.addCircle(width, height, radius, Path.Direction.CCW);
// / 2
Resources resources = getResources();
int color = resources.getColor(R.color.green_back);
Paint paint = new Paint();
paint.setColor(color);
paint.setStrokeWidth(5);
paint.setStyle(Paint.Style.FILL);
float center_x, center_y;
center_x = width / 2;
center_y = height / 2;
final RectF oval = new RectF();
//Formulas :
//SD = Start Degree
//ED = End Degree
//If cakepiece passes 0 (East)
//SD, 360-(SD+ED)
//Else :
//SD, (ED-SD)
oval.set(center_x - radius, center_y - radius, center_x + radius, center_y + radius);
if (End > Start) {
canvas.drawArc(oval, Start, (End - Start), true, paint);
} else if (End < Start) {
canvas.drawArc(oval, Start, ((360 - Start) + End), true, paint);
}
}
}
Im not sure if i explained things right so please tell me if things are unclear :)
I have tried to do this :
public class WindRose extends Activity {
float Start, End;
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public View DrawRose (Context context){
this.context = context;
WindRoseDrawer windRoseDrawer = new WindRoseDrawer(context);
return null; //What should i return here ?
}
private class DrawWindRose extends AsyncTask<String, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(String... strings) {
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
public class WindRoseDrawer extends View {
public WindRoseDrawer(Context context) {
super(context);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
float height = (float) getHeight();
float width = (float) getWidth();
float radius;
if (width > height) {
radius = height / 2;
} else {
radius = width / 2;
}
// radius = (height )/ 2;
Path path = new Path();
path.addCircle(width, height, radius, Path.Direction.CCW);
// / 2
Resources resources = getResources();
int color = resources.getColor(R.color.green_back);
Paint paint = new Paint();
paint.setColor(color);
paint.setStrokeWidth(5);
paint.setStyle(Paint.Style.FILL);
float center_x, center_y;
center_x = width / 2;
center_y = height / 2;
final RectF oval = new RectF();
//Formulas :
//SD = Start Degree
//ED = End Degree
//If cakepiece passes 0 (East)
//SD, 360-(SD+ED)
//Else :
//SD, (ED-SD)
oval.set(center_x - radius, center_y - radius, center_x + radius, center_y + radius);
if (End > Start) {
canvas.drawArc(oval, Start, (End - Start), true, paint);
} else if (End < Start) {
canvas.drawArc(oval, Start, ((360 - Start) + End), true, paint);
}
}
}
}
But how should i implement this back to the SpotDetails ? And what should i return from DrawRose ?
You should draw only in the UI thread. You can't draw in the background if using the Draw inheritance method from View. Better to use a SurfaceView with lock / unlock canvas. It will use an optimized algorithm which allows for background drawing.
#Override
public void run() {
while(locker){
//checks if the lockCanvas() method will be success,and if not, will check this statement again
if(!holder.getSurface().isValid()){
continue;
}
/** Start editing pixels in this surface.*/
Canvas canvas = holder.lockCanvas();
//ALL PAINT-JOB MAKE IN draw(canvas); method.
draw(canvas);
// End of painting to canvas. system will paint with this canvas,to the surface.
holder.unlockCanvasAndPost(canvas);
}
}
Related
I am using magnifier view for my application which is a library I got from here :
https://github.com/nomanr/android-image-magnifier
I have modified this class to extend FrameLayout (It was ImageView before) to work on my FrameLayout.
It's working well except the painted canvas view stays back of all the views which are added in that custom view.
How to bring that canvas on front of those added views?
Custom view class that i am using :
public class ImageMagnifier extends FrameLayout {
private PointF zoomPos;
private boolean zooming = false;
private Matrix matrix;
private Paint paint;
private Bitmap bitmap;
private BitmapShader shader;
private int sizeOfMagnifier = 300;
int cheight, cwidth;
Context con;
C c = C.getInstance();
public ImageMagnifier(Context context) {
super(context);
init();
con=context;
}
public ImageMagnifier(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
con=context;
}
public ImageMagnifier(Context context, AttributeSet attrs) {
super(context, attrs);
init();
con=context;
}
private void init() {
zoomPos = new PointF(0, 0);
matrix = new Matrix();
paint = new Paint();
cwidth = c.Width * 109 / 1280;
cheight = cwidth * 134 / 109;
}
public void otherTouch(int x, int y) {
if (x > c.getwidth1(28) && x < c.getwidth1(921) && y > c.getheight1(135) && y < c.getheight1(560)) {
zoomPos.x = x - 10;
zoomPos.y = y - 75;
zooming = true;
this.invalidate();
} else {
RemoveMagnifire();
}
}
public void RemoveMagnifire() {
zooming = false;
this.invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (!zooming) {
buildDrawingCache();
} else {
bitmap = getDrawingCache();
shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP,Shader.TileMode.CLAMP);
paint.setShader(shader);
matrix.reset();
matrix.postScale(2f, 2f, zoomPos.x-10, zoomPos.y+60);
paint.getShader().setLocalMatrix(matrix);
int width = c.Width;
int height = c.Height;
float leftX = zoomPos.x - ((width * 100) / 1280);
float topY = zoomPos.y - ((height * 250) / 720);
float rightX = zoomPos.x + ((width * 100) / 1280);
float bottomY = zoomPos.y - ((height * 100) / 720);
canvas.drawRect(leftX , topY, rightX, bottomY, paint);
}
}
}
A ViewGroup draws its child Views in the dispatchDraw() method. We just need to move the magnifier drawing to after that happens.
The fix is simple. Move everything after the super call in onDraw() to after the super call in dispatchDraw().
...
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Removed
}
#Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (!zooming) {
buildDrawingCache();
}
else {
bitmap = getDrawingCache();
shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
paint.setShader(shader);
matrix.reset();
matrix.postScale(2f, 2f, zoomPos.x - 10, zoomPos.y + 60);
paint.getShader().setLocalMatrix(matrix);
int width = c.Width;
int height = c.Height;
float leftX = zoomPos.x - ((width * 100) / 1280);
float topY = zoomPos.y - ((height * 250) / 720);
float rightX = zoomPos.x + ((width * 100) / 1280);
float bottomY = zoomPos.y - ((height * 100) / 720);
canvas.drawRect(leftX , topY, rightX, bottomY, paint);
}
}
...
You can just remove the onDraw() override, if you no longer need it for anything else.
I have already an 'ImageView' with these parameters:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
and set custom Drawable :
public class HexDrawable extends Drawable {
private Path hexagonPath;
private float mWidth, mHeight;
private int mBackgroundColor;
private int mStrokeColor;
private int mStrokeWidth;
public HexDrawable(){
init();
}
public void setBackgroundColor(int color) {
mBackgroundColor = color;
}
public void setStrokeWidth(int width) {
mStrokeWidth = width;
}
public void setStrokeColor(int color) {
mStrokeColor = color;
}
#Override
public int getIntrinsicHeight() {
return 60;
}
#Override
public int getIntrinsicWidth() {
return 60;
}
private void init() {
hexagonPath = new Path();
mBackgroundColor = Color.BLUE;
mStrokeColor = Color.GREEN;
mStrokeWidth = 4;
}
private void calculatePath() {
float p = mStrokeWidth / 2;
float w = mWidth - 2 * p;
float h = mHeight - 2 * p;
float r = h / 2;
float a = (float) (r / Math.sqrt(3));
PointF X = new PointF(p + a + r / 2, p);
PointF Y = new PointF(p + a + r , p);
PointF A = new PointF(p + a, p + 0f);
PointF B = new PointF(p + 0f, p + r);
PointF C = new PointF(p + a, p + 2 * r);
PointF D = new PointF(p + w - a, p + 2 * r);
PointF E = new PointF(p + w, p + r);
PointF F = new PointF(p + w - a, p + 0);
hexagonPath.moveTo(Y.x, Y.y);
hexagonPath.lineTo(A.x, A.y);
hexagonPath.lineTo(B.x, B.y);
hexagonPath.lineTo(C.x, C.y);
hexagonPath.lineTo(D.x, D.y);
hexagonPath.lineTo(E.x, E.y);
hexagonPath.lineTo(F.x, F.y);
hexagonPath.lineTo(X.x, X.y);
}
#Override
protected void onBoundsChange(Rect bounds) {
mWidth = bounds.width();
mHeight = bounds.height();
calculatePath();
}
#Override
public void draw(Canvas canvas) {
Paint paint = new Paint();
paint.setColor(mStrokeColor); // set the color
paint.setStrokeWidth(mStrokeWidth); // set the size
paint.setDither(true); // set the dither to true
paint.setStyle(Paint.Style.STROKE); // set to STOKE
paint.setStrokeJoin(Paint.Join.ROUND); // set the join to round you want
paint.setStrokeCap(Paint.Cap.ROUND); // set the paint cap to round too
paint.setPathEffect(new CornerPathEffect(mStrokeWidth)); // set the path effect when they join.
paint.setAntiAlias(true);
canvas.drawPath(hexagonPath, paint);
canvas.clipPath(hexagonPath, Region.Op.INTERSECT);
canvas.drawColor(mBackgroundColor);
canvas.drawPath(hexagonPath, paint);
canvas.save();
}
#Override
public void setAlpha(int alpha) {
}
#Override
public void setColorFilter(ColorFilter colorFilter) {
}
#Override
public int getOpacity() {
return 0;
}
}
It seems that ImageView use all width in this case.
How to implements Drawable correctly to use it with ImageView?
The root of the problem was clip mode.
Its better to use canvas.clipPath(hexagonPath, Region.Op.REPLACE);
Also, question example works well with ImageView, but after deep investigation I undestand, that at android 5.0 and above this drawable is used at drawableLeft in TextView.
Also its not need to override getIntrinsicHeight
Your code is absolutely correct:
This is how I fill ImageView (in onCreate() of activity):
((ImageView)findViewById(R.id.hexImageView)).setImageDrawable(new HexDrawable());
Layout of the Activity on the screenshot:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp">
<ImageView
android:id="#+id/hexImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</FrameLayout>
If I replace wrap_content with value, hexagon as expected is changing its size.
Tested on Android 6.0 and 4.3.
Just one tip - instead of hardcoded values in getIntrinsicHeight() and getIntrinsicWidth(), it might be better to use dimens instead.
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.
I am inspired by the the new Material Design animations and I worked to create a similar drawable that is used in new support v7 Action Bar Drawer Toggle.
I created a CustomDrawable. All I actually did is that I created a Play triangle on canvas and pause logo on the left of the left margin of the visible canvas. I rotate the canvas according to the progress and restore it. Then I used Xfermode to crop the rotated result into a circle.
I cant find the solution to the problem.
The problem is that the xFermode is not applied to the 180 degree rotated result(after calling canvas.restore()).
Here is the code of Activity.
public class MainActivity extends Activity{
ImageView iv;
CustomDrawable drawable = new CustomDrawable();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
iv = (ImageView) findViewById(R.id.button);
iv.setLayerType(View.LAYER_TYPE_HARDWARE, null);
iv.setBackgroundDrawable(drawable);
iv.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
float[] values = { 0, 1 };
if (drawable.getProgress() != 0) {
values[0] = drawable.getProgress();
values[1] = 0;
}
ObjectAnimator animator = ObjectAnimator.ofFloat(drawable,
"progress", values);
animator.setDuration(2000);
animator.start();
}
});
}
}
And the code for the CustomDrawable
public class CustomDrawable extends Drawable {
private float mProgress = 0;
private Paint mPaint = new Paint();
private Path mPath = new Path();
private final float rootTwo = (float) Math.sqrt(2);
private final float rootThree = (float) Math.sqrt(3);
private float radius = 0;
private float side = 0;
private Point[] triangle = new Point[3];
Paint xferpaint = new Paint();
Canvas cropper;
Bitmap bitmap;
Interpolator interpolator = new AnticipateOvershootInterpolator();
private float width;
Rect rec1, rec2;
public CustomDrawable() {
mPaint.setAntiAlias(true);
mPaint.setStyle(Style.FILL);
xferpaint.setColor(Color.RED);
xferpaint.setStyle(Style.FILL);
xferpaint.setAntiAlias(true);
}
#Override
public void draw(Canvas canvas) {
canvas.getClipBounds(bound);
boundsf.set(bound);
if (radius == 0) {
radius = Math.min(bound.centerX(), bound.centerY());
radius -= 5;
bitmap = Bitmap.createBitmap(bound.width(), bound.height(),
Config.ARGB_8888);
cropper = new Canvas(bitmap);
cropper.drawCircle(bound.centerX(), bound.centerY(), radius,
xferpaint);
xferpaint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
side = rootTwo * radius;
triangle[0] = new Point(
(int) (bound.centerX() + (side / rootThree)),
bound.centerY());
triangle[1] = new Point(bound.centerX()
- (int) (side / (2 * rootThree)), bound.centerY()
- (int) (side / 2));
triangle[2] = new Point(bound.centerX()
- (int) (side / (2 * rootThree)), bound.centerY()
+ (int) (side / 2));
width = side / 4;
rec1 = new Rect((int) (-bound.centerX() - (3 * width / 2)),
(int) (bound.centerY() - (side / 2)),
(int) (-bound.centerX() - (width / 2)),
(int) (bound.centerY() + (side / 2)));
rec2 = new Rect((int) (-bound.centerX() + (width / 2)),
(int) (bound.centerY() - (side / 2)),
(int) (-bound.centerX() + (3 * width / 2)),
(int) (bound.centerY() + (side / 2)));
}
mPath.rewind();
mPath.moveTo(triangle[0].x, triangle[0].y);
mPath.lineTo(triangle[1].x, triangle[1].y);
mPath.lineTo(triangle[2].x, triangle[2].y);
mPath.close();
mPaint.setColor(Color.parseColor("#378585"));
canvas.drawPaint(mPaint);
mPaint.setColor(Color.parseColor("#FF0400"));
canvas.rotate(180 * interpolator.getInterpolation(mProgress), 0,
bound.centerY());
canvas.drawPath(mPath, mPaint);
canvas.drawRect(rec1, mPaint);
canvas.drawRect(rec2, mPaint);
canvas.restore();
canvas.drawBitmap(bitmap, 0, 0, xferpaint);
}
#Override
public int getOpacity() {
return mPaint.getAlpha();
}
#Override
public void setAlpha(int alpha) {
mPaint.setAlpha(alpha);
}
#Override
public void setColorFilter(ColorFilter filter) {
mPaint.setColorFilter(filter);
}
public float getProgress() {
return mProgress;
}
public void setProgress(float progress) {
mProgress = progress;
invalidateSelf();
}
}
this is your simplified Drawable:
class CustomDrawable extends Drawable implements ValueAnimator.AnimatorUpdateListener {
private float mProgress = 0;
private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
private Path mPath;
private Path mClipPath;
public CustomDrawable() {
mPaint.setStyle(Paint.Style.FILL);
mPaint.setColor(0xffFF0400);
}
#Override
protected void onBoundsChange(Rect bounds) {
mClipPath = new Path();
int cx = bounds.centerX();
int cy = bounds.centerY();
int radius = Math.min(cx, cy) - 5;
mClipPath.addCircle(cx, cy, radius, Path.Direction.CCW);
final float rootTwo = (float) Math.sqrt(2);
final float rootThree = (float) Math.sqrt(3);
float side = rootTwo * radius;
mPath = new Path();
mPath.moveTo(cx + (side / rootThree), cy);
mPath.lineTo(cx - side / (2 * rootThree), cy - side / 2);
mPath.lineTo(cx - side / (2 * rootThree), cy + side / 2);
mPath.close();
float width = side / 4;
addRect(-cx - (3 * width / 2), cy - (side / 2), width, side);
addRect(-cx + (width / 2), cy - (side / 2), width, side);
}
private void addRect(float l, float t, float dx, float dy) {
mPath.addRect(l, t, l + dx, t + dy, Path.Direction.CCW);
}
#Override
public void draw(Canvas canvas) {
canvas.clipPath(mClipPath);
canvas.drawColor(0xff378585);
Rect bounds = getBounds();
canvas.rotate(mProgress, 0, bounds.centerY());
canvas.drawPath(mPath, mPaint);
}
public void switchIcons() {
float[] values = { 0, 180 };
if (mProgress != 0) {
values[0] = mProgress;
values[1] = 0;
}
ValueAnimator animator = ValueAnimator.ofFloat(values).setDuration(2000);
animator.setInterpolator(new AnticipateOvershootInterpolator());
animator.addUpdateListener(this);
animator.start();
}
#Override
public void onAnimationUpdate(ValueAnimator animation) {
mProgress = (Float) animation.getAnimatedValue();
invalidateSelf();
}
#Override
public int getOpacity() {
return mPaint.getAlpha();
}
#Override
public void setAlpha(int alpha) {
mPaint.setAlpha(alpha);
}
#Override
public void setColorFilter(ColorFilter filter) {
mPaint.setColorFilter(filter);
}
}
EDIT: this is draw() method without Canvas.clipPath and without creating a "mask" Bitmap:
#Override
public void draw(Canvas canvas) {
canvas.drawColor(0xff378585);
canvas.save();
canvas.rotate(mProgress, 0, cy);
canvas.drawPath(mPath, mPaint);
canvas.restore();
canvas.saveLayer(null, mDstInPaint, 0);
canvas.drawCircle(cx, cy, radius, mPaint);
canvas.restore();
}
where: mDstInPaint is a Paint object with xfermode set in Drawable's constructor:
mDstInPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
I am trying to create in game gravity in Android. I created an update method, a display, and gravity. Right now the app does not force close, but the ball just doesn't move. Do I need to use a canvas for the .getHieght() and .getWidth() methods?
public class MainActivity extends Activity {
private int c = Color.YELLOW;
private Canvas g;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
draw();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
// draws the ball
public void draw ()
{
Display display = getWindowManager().getDefaultDisplay();
int width = display.getHeight();
int height = display.getWidth();
Bitmap bitmap = Bitmap.createBitmap(width, height, Config.RGB_565);
g = new Canvas(bitmap);
g.drawColor(c);
Paint paint = new Paint();
paint.setColor(Color.BLACK);
g.drawCircle(50, 10, 25, paint); //Put your values
update();
// In order to display this image, we need to create a new ImageView that we can display.
ImageView imageView = new ImageView(this);
// Set this ImageView's bitmap to ours
imageView.setImageBitmap(bitmap);
// Create a simple layout and add imageview to it.
RelativeLayout layout = new RelativeLayout(this);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.CENTER_IN_PARENT);
layout.addView(imageView, params);
layout.setBackgroundColor(Color.BLACK);
// Show layout in activity.
setContentView(layout);
}
private void update(){
// wall collisions;
if (x + dx > sp.getWidth() - radius - 1) {
x = sp.getWidth() - radius - 1;
// bounce off right wall;
dx = -dx;
// bounce off left wall;
} else if (x + dx < 0 + radius) {
x = 0 + radius;
dx = -dx;
} else {
x += dx;
}
// friction;
if (y == sp.getHeight() - radius - 1) {
dx *= xFriction;
if (Math.abs(dx) < .8) {
dx = 0;
}
}
// gravity;
if (y > sp.getHeight() - radius - 1) {
y = sp.getHeight() - radius - 1;
dy *= energyloss;
dy = -dy;
} else {
// velocity formula;
dy += gravity * dt;
// position formula;
y += dy * dt + .5 * gravity * dt * dt;
}
}
}
In my opinion, your approach is all wrong and is creating complexity.
Here's how I'd do it. Create two classes, one for the ball and one for somewhere to draw it. Something along these lines:
public class Ball{
private int radius;
private int xPosition;
private int yPosition;
private int color;
private Paint paint;
public Ball(int x, int y, int radius, int color)
{
this.xPosition = x; this.yPosition = y; this.radius = radius;
paint = new Paint(color);
}
void moveBall(int x, int y){
xPosition = x; yPosition =y;
}
void onDraw(Canvas canvas){
canvas.drawCircle(x, y, radius, paint);
}
}
Now somewhere to draw it.
public class Playground extends ImageView{
public Ball ball;
#Override
public void onDraw(Canvas canvas)
{
super.onDraw(canvas);
if (ball != null ){
ball.onDraw(canvas);
}
}
}
In your activity, probably in onStart():
imageView.ball = new Ball(startX, startY, radius, Color.BLUE);
Move your "update" method into the ball class also and call ball.update() on a timer (or whenever you want to update it).
Replace the ImageView in your layout with the Playground class (first name that popped into my head).
Override onMeasure() in the ImageView extension to get height and width of the "playground".
That gives you the basics. I wrote this off the top of my head so please excuse typos etc
Also, review the answers given to you in your multiple previous questions on this topic and read the Android documentation on extending View classes, onDraw and onMeasure.
I think you're drawing just once, you may add a timer to trigger the draw() method