Develop Reference

How to design a custom progress bar with rounded edges and slanting progress?

This is what I wish to achieve:
Clicky
The container color, the progress color, the progress background color and the rounded edge radius as well as the thickness should all be editable and modifiable.
How could this be achieved with a light weight custom UI element?

After days of research, I was able to achieve what was expected with clear crisp UI and with all the above requirements and flexibility. The exact above UI can be achieved and follow parameters can be achieved as well:
1. Progress Color
2. Progress background color
3. Container color (Color of container to be set by you, you can set color of rounded edges to match the container color)
4. Height and width of the progress bar to suit your needs.
Here's the code and steps to implement it:
I. Put this code in the attrs.xml file under the values folder
<declare-styleable name="SlantingProgressBar">
<attr name="slantingProgress" format="integer"/>
<attr name="borderRadius" format="integer"/>
<attr name="borderColor" format="integer"/>
<attr name="slantingProgressColor" format="string"/>
<attr name="progressBackgroundColor" format="string"/>
<attr name="slantingProgressFullColor" format="string"/>
</declare-styleable>
II. Create a java class like this:
public class SlantingProgressbar extends View {
private float height = 0;
private float width = 0;
private int borderRadius = 20;
private float progress = 0;
private int rawProgress = 0;
private static final String OPACITY_30_PERCENT = "#66";
private int roundedBorderColor;
private String backgroundColor = "";
private String progressColor = "";
private String progressFullColor = "#fc3d39";
public SlantingProgressbar(Context context) {
super(context);
}
public SlantingProgressbar(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray array = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.SlantingProgressBar,
0, 0);
try {
setProgress(array.getInt(R.styleable.SlantingProgressBar_slantingProgress, 0));
setBackgroundColor(array.getString(R.styleable.SlantingProgressBar_progressBackgroundColor)); //Default color set in the method
setBorderRadius(array.getInt(R.styleable.SlantingProgressBar_borderRadius, 20));
setRoundedBorderColor(array.getInt(R.styleable.SlantingProgressBar_borderColor, 0));
setProgressColor(array.getString(R.styleable.SlantingProgressBar_slantingProgressColor));
} finally {
array.recycle();
}
}
public void setBorderRadius(int borderRadius) {
this.borderRadius = borderRadius;
}
public int getProgress() {
return rawProgress;
}
public void setProgress(int progress) {
if(progress >=0)
{
this.rawProgress = progress;
this.invalidate();
}
else
Log.e("ChlorophyllProgressBar", "Invalid 'progress' value detected, value should be between 0 and 100");
}
public void setRoundedBorderColor(int roundedBorderColor) {
if ( roundedBorderColor == 0) {
this.roundedBorderColor = getResources().getColor(R.color.white);
Log.e("CUSTOM_TAG", "Color set to White: " + this.roundedBorderColor);
return;
}
this.roundedBorderColor = roundedBorderColor;
Log.e("CUSTOM_TAG", "Color set to custom: " + this.roundedBorderColor);
}
private int getRoundedBorderColor()
{
return roundedBorderColor;
}
public void setSlantingProgressFullColor(String color)
{
if (TextUtils.isEmpty(progressFullColor)) {
this.progressFullColor = "#fc3d39";
return;
}
}
public void setBackgroundColor(String backgroundColor) {
if (TextUtils.isEmpty(backgroundColor)) {
this.backgroundColor = "#bfe8d4";
return;
}
this.backgroundColor = backgroundColor;
}
public void setProgressColor(String progressColor) {
if (TextUtils.isEmpty(progressColor)) {
this.progressColor = "#2bb673"; //Green
return;
}
this.progressColor = progressColor;
}
public float getViewHeight() {
return height;
}
public void setViewHeight(float height) {
this.height = height;
}
public float getViewWidth() {
return width;
}
public void setViewWidth(float width) {
this.width = width;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
height = getHeight();
width = getWidth();
progress = getProcessedProgress();
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.parseColor(backgroundColor));
canvas.drawPaint(paint);
paint.setColor(getProcessedProgressColor());
paint.setAntiAlias(true);
Log.d("CUSTOM_TAG", "Height: " + height);
canvas.drawRect(0, 0, progress, height, paint);
Path triangle = new Path();
triangle.setFillType(Path.FillType.EVEN_ODD);
triangle.moveTo(progress, 0);
triangle.lineTo(progress + height, 0);
triangle.lineTo(progress, height);
triangle.close();
canvas.drawPath(triangle, paint);
drawBorders(canvas, getRoundedBorderColor());
}
private void drawBorders(Canvas canvas, int color) {
float height = getHeight();
float trueWidth = getWidth();
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(color);
//paint.setColor(getResources().getColor(R.color.white));
paint.setAntiAlias(true);
Path border = new Path();
border.moveTo(0, 0);
border.lineTo(0, height / 2);
border.quadTo(height / borderRadius, height / borderRadius, height / 2, 0);
border.lineTo(0, 0);
canvas.drawPath(border, paint);
border.reset();
border.moveTo(0, height);
border.lineTo(height / 2, height);
border.quadTo(height / borderRadius, (height - height / borderRadius), 0, height / 2);
border.lineTo(0, height);
canvas.drawPath(border, paint);
border.reset();
border.moveTo(trueWidth, 0);
border.lineTo(trueWidth - (height / 2), 0);
border.quadTo((trueWidth - height / borderRadius), height / borderRadius, trueWidth, height / 2);
border.lineTo(trueWidth, 0);
canvas.drawPath(border, paint);
border.reset();
border.moveTo(trueWidth, height);
border.lineTo(trueWidth - (height / 2), height);
border.quadTo((trueWidth - height / borderRadius), (height - height / borderRadius), trueWidth, height / 2);
border.lineTo(trueWidth, height);
canvas.drawPath(border, paint);
//Adding 1 pixel color
Paint paint1 = new Paint();
paint1.setStyle(Paint.Style.FILL);
int fadedColor = (color & 0x00FFFFFF) | 0x66000000;
Log.d("CUSTOM_TAG", "Faded Color Code: " + fadedColor);
paint1.setColor(fadedColor);
canvas.drawRect(0, 0, 1, height, paint1);
canvas.drawRect(trueWidth-1, 0, trueWidth, height, paint1);
}
private float getProcessedProgress()
{
return (rawProgress == 99) ? ((getWidth() * 98) / 100) : ((getWidth() * rawProgress) / 100);
}
private int getProcessedProgressColor()
{
if(rawProgress > 100)
{
return Color.parseColor(progressFullColor);
}
else
{
return Color.parseColor(progressColor);
}
}
}
III. To use the layout in your xml file:
<com.whatever.package.SlantingProgressbar
android:id="#+id/progressbar_detail"
android:layout_width="match_parent"
android:layout_height="#dimen/dimension1"
android:layout_alignParentLeft="true"
slanting_progress:borderColor="#color/darkgray"
android:layout_below="#id/alphacon_detail"
android:layout_marginBottom="#dimen/budget_list_item_paddingBottom"
android:progress="50" />
I'm sharing this code after a little while, so I might have missed out a thing or two, I'm pretty sure you can get that worked out, please feel free to correct me.
Explanation:
We're using the 'draw' methods in java to implement this feature. The advantage is that, drawing a UI element gives us a sharp and clear UI no matter how big or small you make it.
There might be some hardcoded values, so be sure to edit those before implementing.
Good luck and don't forget to up-vote if this post helps you. Thanks! :)

I'll post an answer here to show some improvements on your code.
You should avoid creating new objects during draw.
draw is called several times again and again to redraw your custom element and all those calls to new Paint() are creating new objects, that needs new memory allocation, and it drives the garbage collector crazy and makes your View much more resource intensive and probably will cause lag on scrolling elements such as RecyclerView.
Alternatively you should have them declared as private Paint border and then private Paint triangle, etc, etc. And then you should initialise the values of All the paints in a separate method and only if the parameters changed. An example code:
private boolean initPaint = false;
private void initPaintsIfNecessary(){
if(!initPaint) return;
initPaint = false;
triangle = new Paint();
triangle.set.... etc
border = new Paint();
border.set.... etc
}
then on all the methods setRoundedBorderColor, setProgressColor, etc. You call initPaint = true; and on the beginning of draw you call initPaintsIfNecessary();. This will avoid all the extra garbage collector work and will allow the UI of your app to run much smoother.
That also includes all the Paint inside drawBorders method.
use format="color" instead ofstring`.
Calling Color.parse(String) is a very slow call and it is very error prone. Alternatively you should the correct color element, like following:
<attr name="slantingProgressColor" format="color"/>
that not just is the correct way, but gives you a color preview on the editor, can be indexed on app style parameters and avoid this inefficient call to parse
then of course you should adjust or method appriately. For example:
setProgressColor(array.getColor(R.styleable.SlantingProgressBar_slantingProgressColor));
getColor will return an integer that can be directly used in paint.setColor(int);
I hope those tips can help you (and others in the community) to create better more efficient View elements. Happy coding!

I know this this old question to answer but this answer may helpful..
You can use drawArc method to achieve this..
RectF oval = new RectF();
oval.set(left, top ,right, bottom);
canvas.drawArc(oval, 270, 360, false, paint);

Android TransitionDrawable not fading

I have an ImageView and I am trying to fade from one image to the next using this code:
Drawable bgs[] = new Drawable[2];
public void redraw(int[][] grid) {
bgs[0] = bgs[1];
bgs[1] = new GameDrawable(grid, prefs.colors);
if (bgs[0] == null) {
gameField.setImageDrawable(bgs[1]);
} else {
TransitionDrawable crossfader = new TransitionDrawable(bgs);
crossfader.setCrossFadeEnabled(true);
gameField.setImageDrawable(crossfader);
crossfader.startTransition(500);
}
}
gameField is correctly referenced as an ImageView.
gameDrawable simply extends Drawable and draws the grid.
On each move and action the new GameDrawable is being rendered correctly but there is no fading whatsoever. The new image is simply displayed instantaneously. I have tried lengthening the transition time and swapping the order of the drawables with no effect.
Any help on is appreciated.
Update: I have now set my transition to something ridiculously long like 500000. The first drawable shows for a few seconds and then suddenly the second drawable appears. So still no transition.
Update 2:
I think my Drawable might be implemented incorrectly, so I have attached the code.
public class GameDrawable extends Drawable {
private Paint paint = new Paint();
private float blockWidth = 1;
private int[][] myGrid;
private int myColor;
private List<Point> myPoints;
public GameDrawable(int[][] grid) {
super();
this.myGrid = grid;
this.myColor = colors[yourColor];
paint.setStrokeWidth(1);
paint.setStyle(Paint.Style.FILL);
paint.setAlpha(0);
this.myPoints = yourPoints;
}
#Override
public void draw(Canvas canvas) {
float height = getBounds().height();
float width = getBounds().width();
blockWidth = width / myGrid.length;
if (height / myGrid.length < blockWidth) {
blockWidth = height / myGrid.length;
}
for (int x = 0; x < myGrid.length; x++) {
for (int y = 0; y < myGrid[x].length; y++) {
paint.setColor(colors[myGrid[x][y]]);
canvas.drawRect(x * blockWidth, y * blockWidth, (x+1)*blockWidth, (y+1)*blockWidth, paint);
}
}
}
#Override
public void setAlpha(int alpha) {
paint.setAlpha(alpha);
invalidateSelf();
}
#Override
public void setColorFilter(ColorFilter cf) {
paint.setColorFilter(cf);
invalidateSelf();
}
#Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
}

Looking at your code, I see a problem at the line
bgs[0] = bgs[1];
bgs[1] has not yet been defined before this line and so bgs[0] is null for the first method call. Because of this, (bgs[0] == null) is true, and so the later defined bgs[1] is directly set to the gameField ImageView.
Use corrected code below.
Drawable bgs[] = new Drawable[2];
Drawable firstDrawable = getResources().getDrawable(R.drawable.transparent);
public void redraw(int[][] grid) {
bgs[0] = firstDrawable;
bgs[1] = new GameDrawable(grid, prefs.colors);
firstDrawable = bgs[1];
TransitionDrawable crossfader = new TransitionDrawable(bgs);
crossfader.setCrossFadeEnabled(true);
gameField.setImageDrawable(crossfader);
crossfader.startTransition(500);
}
Note that TransitionDrawable does not work properly when the Drawable sizes are different. So you may need to resize firstDrawable beforehand.
EXTRA: I would avoid setCrossFadeEnabled(true) since the whole TransitionDrawable becomes translucent during the transition, revealing the background. Sometimes, this creates a "blinking" effect and destroys the smoothness of the transition.
EDIT: Looking at your custom Drawable implementation, I think the problem lies in the line
canvas.drawColor(Color.WHITE);
in the draw() method.
I looked at TransitionDrawable.java source and found that setAlpha is called on the drawables to get the cross fade effect. However, your canvas has a solid white color and setAlpha() only affects the paint. Hope this is your answer.
EDIT 2: The actual problem, as pointed out by Michael, was that TransitionDrawable's setAlpha() calls on the Drawables were rendered ineffective due to paint.setColor() in the GameDrawable's draw() method overriding the paint's alpha value set by the TransitionDrawable.

Android: Making Bitmaps Disappear When Touched

As is, 100 pink circles (same bitmap) appear scattered randomly over the phone screen (as is supposed to). When I tap one of the circles, that circle should disappear (change to the background color). I think I have a fundamental misunderstanding of Android and View in general.I think I have a couple obvious errors (that are not so obvious to me, but I've been staring at it so long that I figured I needed some help). Currently, the screen shows the random circles but nothing more. Touching the screen does nothing. Any better ideas to make the circles disappear? It recently reorganized all the bitmaps when you touched it, but I did something recently, and it stopped. The bitmap is 30px by 30px.
public class DrawV extends View {
private Bitmap bit_dot;
private int width;
private int height;
public int[] width_array = new int[100];
public int[] height_array = new int[100];
private View dotV = (View)findViewById(R.id.bigdocpic);//bitmap
Random rand = new Random();
public DrawV(Context context) {
super(context);
bit_dot = BitmapFactory.decodeResource(getResources(), R.drawable.dot_catch);
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
width = metrics.widthPixels;
height = metrics.heightPixels;
}
#Override
//draws 100 randomly placed similar bitmaps
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int height_dimension;
int width_dimension;
for (int i = 0; i < 100; i++){
height_dimension = rand.nextInt(height) + 1;
width_dimension = rand.nextInt(width) + 1;
canvas.drawBitmap(bit_dot, width_dimension, height_dimension, null);
width_array[i] = width_dimension;//
height_array[i] = height_dimension;//
}
}
#Override
public boolean onTouchEvent(MotionEvent event){
Paint p = new Paint();
p.setColor(Color.WHITE);
Path path = new Path();
Canvas c = new Canvas();
for (int i = 0; i < 100; i++){
if ((event.getX() == width_array[i]) && (event.getY() == height_array[i]))
c.drawCircle(width_array[i], height_array[i], 15, p);
}
invalidate();
return false;//false or true?
}
//set visibility of bitmap to invisible
public boolean onTouch(View v, MotionEvent event) {
dotV.setVisibility(View.INVISIBLE);
invalidate();
return false;//false or true? not understanding
}}
Help?

Your onTouchEvent isn't really doing anything important as-is, and you don't have the concept of a circle object.
onDraw should really be drawing these circles from an array/list created earlier - say a List<MyCircles> or MyCircles[]. On touch, you could iterate through all of your circles until you find one that is closest, remove that circle from the array or list, then invalidate.
The reason nothing is happening at all is even though you're drawing those circles again in onTouchEvent, you're redrawing everything yet again in onDraw (invalidate() calls draw/onDraw).
Ideally, create your list of circles in your initializer, draw them in onDraw, and update them in onTouch (That is, delete). There may be a simpler way to do this but this is, at the very least, a more proper approach.

Android : Semi Circle Progress Bar

I want semi circle progress bar in background of image. just like below image.
i have tried to draw using canvas but can't get success. i have also tired some custom progress bar library but result is same.
any suggestions.
looking for one time development and used in every screen size.

This can be implemented by clipping a canvas containing an image at an angle (By drawing an arc).
You can use an image something like this
And clip that image by drawing an arc.
Here is how you can do it.
//Convert the progress in range of 0 to 100 to angle in range of 0 180. Easy math.
float angle = (progress * 180) / 100;
mClippingPath.reset();
//Define a rectangle containing the image
RectF oval = new RectF(mPivotX, mPivotY, mPivotX + mBitmap.getWidth(), mPivotY + mBitmap.getHeight());
//Move the current position to center of rect
mClippingPath.moveTo(oval.centerX(), oval.centerY());
//Draw an arc from center to given angle
mClippingPath.addArc(oval, 180, angle);
//Draw a line from end of arc to center
mClippingPath.lineTo(oval.centerX(), oval.centerY());
And once you get the path, you can use clipPath function to clip the canvas in that path.
canvas.clipPath(mClippingPath);
Here is the Complete code
SemiCircleProgressBarView.java
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;
public class SemiCircleProgressBarView extends View {
private Path mClippingPath;
private Context mContext;
private Bitmap mBitmap;
private float mPivotX;
private float mPivotY;
public SemiCircleProgressBarView(Context context) {
super(context);
mContext = context;
initilizeImage();
}
public SemiCircleProgressBarView(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
initilizeImage();
}
private void initilizeImage() {
mClippingPath = new Path();
//Top left coordinates of image. Give appropriate values depending on the position you wnat image to be placed
mPivotX = getScreenGridUnit();
mPivotY = 0;
//Adjust the image size to support different screen sizes
Bitmap bitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.circle);
int imageWidth = (int) (getScreenGridUnit() * 30);
int imageHeight = (int) (getScreenGridUnit() * 30);
mBitmap = Bitmap.createScaledBitmap(bitmap, imageWidth, imageHeight, false);
}
public void setClipping(float progress) {
//Convert the progress in range of 0 to 100 to angle in range of 0 180. Easy math.
float angle = (progress * 180) / 100;
mClippingPath.reset();
//Define a rectangle containing the image
RectF oval = new RectF(mPivotX, mPivotY, mPivotX + mBitmap.getWidth(), mPivotY + mBitmap.getHeight());
//Move the current position to center of rect
mClippingPath.moveTo(oval.centerX(), oval.centerY());
//Draw an arc from center to given angle
mClippingPath.addArc(oval, 180, angle);
//Draw a line from end of arc to center
mClippingPath.lineTo(oval.centerX(), oval.centerY());
//Redraw the canvas
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//Clip the canvas
canvas.clipPath(mClippingPath);
canvas.drawBitmap(mBitmap, mPivotX, mPivotY, null);
}
private float getScreenGridUnit() {
DisplayMetrics metrics = new DisplayMetrics();
((Activity)mContext).getWindowManager().getDefaultDisplay().getMetrics(metrics);
return metrics.widthPixels / 32;
}
}
And using it in any activity is very easy.
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.progressbardemo.SemiCircleProgressBarView
android:id="#+id/progress"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
Note that clipPath function doesn't work if the hardware acceleration is turned on. You can turn off the hardware acceleration only for that view.
//Turn off hardware accleration
semiCircleProgressBarView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
MainActivity.java
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SemiCircleProgressBarView semiCircleProgressBarView = (SemiCircleProgressBarView) findViewById(R.id.progress);
semiCircleProgressBarView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
semiCircleProgressBarView.setClipping(70);
}
}
As and when the progress changes you can set the progressbar by calling function,
semiCircleProgressBarView.setClipping(progress);
Ex: semiCircleProgressBarView.setClipping(50); //50% progress
semiCircleProgressBarView.setClipping(70); //70% progress
You can use your own Image to match the requirements. Hope it helps!!
Edit : To move the semi circle to bottom of the screen, change mPivotY value. Something like this
//In `SemiCircleProgressBarView.java`
//We don't get the canvas width and height initially, set `mPivoyY` inside `onWindowFocusChanged` since `getHeight` returns proper results by that time
public void onWindowFocusChanged(boolean hasWindowFocus) {
super.onWindowFocusChanged(hasWindowFocus);
mPivotX = getScreenGridUnit();
mPivotY = getHeight() - (mBitmap.getHeight() / 2);
}

You can try SeekArc Library. I know its a different kind of seekbar, but with some minor customization, you can use it for your app as a progressbar. I've done the same. You just need to change some properties like seekarc:touchInside="false".
Its fairly simple.
Now the custom implementation on my app looks somewhat like this:
img src: CleanMaster at Google Play

You can also use native ProgressBar to achieve semi circle.
Define ProgressBar like this:
<ProgressBar
android:id="#+id/progressBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:max="200"
android:progress="0"
android:progressDrawable="#drawable/circular" />
Create drawable:
circular (API Level < 21):
<shape
android:innerRadiusRatio="2.3"
android:shape="ring"
android:thickness="5sp" >
<solid android:color="#color/someColor" />
</shape>
circular (API Level >= 21):
<shape
android:useLevel="true"
android:innerRadiusRatio="2.3"
android:shape="ring"
android:thickness="5sp" >
<solid android:color="#color/someColor" />
</shape>
useLevel is false by default in API Level 21.
Now since we have set max = 200, to achieve semi circle, range of the progress should be 0 to 100. You can play around with these values to achieve desired shape.
Thus use it like this:
ProgressBar progressBar = (Progressbar) view.findViewById(R.id.progressBar);
progressBar.setProgress(value); // 0 <= value <= 100

This is a view which has height equal to half its width.
Use the setters to adjust the behaviour as desired.
By default the progress is 0 and the width of the arc is 20.
Calling setProgress() will invalidate the view with the progress given.
Adding a background drawable is possible and the progress bar will be draw on top.
public class SemicircularProgressBar extends View {
private int mProgress;
private RectF mOval;
private RectF mOvalInner;
private Paint mPaintProgress;
private Paint mPaintClip;
private float ovalsDiff;
private Path clipPath;
public SemicircularProgressBar(Context context) {
super(context);
init();
}
public SemicircularProgressBar(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public SemicircularProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mProgress = 0;
ovalsDiff = 20;
mOval = new RectF();
mOvalInner = new RectF();
clipPath = new Path();
mPaintProgress = new Paint();
mPaintProgress.setColor(Color.GREEN);
mPaintProgress.setAntiAlias(true);
mPaintClip = new Paint();
mPaintClip.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
mPaintClip.setAlpha(0);
mPaintClip.setAntiAlias(true);
}
// call this from the code to change the progress displayed
public void setProgress(int progress) {
this.mProgress = progress;
invalidate();
}
// sets the width of the progress arc
public void setProgressBarWidth(float width) {
this.ovalsDiff = width;
invalidate();
}
// sets the color of the bar (#FF00FF00 - Green by default)
public void setProgressBarColor(int color){
this.mPaintProgress.setColor(color);
}
#Override
public void onDraw(Canvas c) {
super.onDraw(c);
mOval.set(0, 0, this.getWidth(), this.getHeight()*2);
mOvalInner.set(0+ovalsDiff, 0+ovalsDiff, this.getWidth()-ovalsDiff, this.getHeight()*2);
clipPath.addArc(mOvalInner, 180, 180);
c.clipPath(clipPath, Op.DIFFERENCE);
c.drawArc(mOval, 180, 180f * ((float) mProgress / 100), true, mPaintProgress);
}
// Setting the view to be always a rectangle with height equal to half of its width
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
this.setMeasuredDimension(parentWidth/2, parentHeight);
ViewGroup.LayoutParams params = this.getLayoutParams();
params.width = parentWidth;
params.height = parentWidth/2;
this.setLayoutParams(params);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

You can use this library :
compile 'com.github.lzyzsd:circleprogress:1.1.1'
for example :
<com.github.lzyzsd.circleprogress.DonutProgress
android:layout_marginLeft="50dp"
android:id="#+id/donut_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
custom:donut_progress="30"/>
<com.github.lzyzsd.circleprogress.ArcProgress
android:id="#+id/arc_progress"
android:background="#214193"
android:layout_marginLeft="50dp"
android:layout_width="100dp"
android:layout_height="100dp"
custom:arc_progress="55"
custom:arc_bottom_text="MEMORY"/>
For more information see the following website :
https://github.com/lzyzsd/CircleProgress

You may be able to use this github library - circularseekbar. To achieve the half circle, you will need to manipulate the following attributes: "app:start_angle" & "app:end_angle"
More Options:
The Holo Seekbar library
Tutorial showing semi-circular seekbar link to tutorial

How to make an Android app that prints touched points and draw them?

I want to make a small app. You will touch the screen and draw something and it will list points you pass and draw small green 3x3 rectangles for each fifth point. I use onTouchEvent for listing points using TextView and send it to setContentView. However, I have problem in drawing. I checked examples for drawing (onDraw) but I am not able to get it working for both printing point plus drawing green dots. Any help would be great, thanks.

Here you are, a quick sample of drawing on SurfaceView.
public class FunPanel extends SurfaceView {
class Point {
int X;
int Y;
public Point() {
X = Y = -1;
}
}
private ArrayList<Point> mPoints = new ArrayList<Point>();
private Point mCurPoint = new Point();
private Bitmap mBitmap = ....// your desired image
#Override
public void doDraw(Canvas canvas) {
if( !(mPoints.size() % 5) ) {
canvas.drawBitmap(mBitmap, mCurPoint.X, mCurPoint.Y, null);
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
mCurPoint.X = (int) event.getX() - mBitmap.getWidth() / 2;
mCurPoint.Y = (int) event.getY() - mBitmap.getHeight() / 2;
mPoints.add(mCurPoint);
return super.onTouchEvent(event);
}
}

It's not entirely clear what you're trying to do, but have a look at this It should get you started in the right direction. Basically extend a View and override the onDraw(Canvas) to draw the Rectangles and override the onTouchEvent(MotionEvent) to grab the touch points from the screen.