add support for specifying a static position for dot on CircularProgressIndicator

circularprogressindicator/src/main/java/antonkozyriatskyi/circularprogressindicator/CircularProgressIndicator.java

@@ -67,6 +67,7 @@ public class CircularProgressIndicator extends View {
     private static final int DEFAULT_ANIMATION_DURATION = 1_000;
 
     private static final String PROPERTY_ANGLE = "angle";
+    private static final int DEFAULT_DOT_ANGLE_POSITION = -1;
 
 
     private Paint progressPaint;
@@ -76,6 +77,7 @@ public class CircularProgressIndicator extends View {
 
     private int startAngle = DEFAULT_PROGRESS_START_ANGLE;
     private int sweepAngle = 0;
+    private int dotAnglePosition = DEFAULT_DOT_ANGLE_POSITION;
 
     private RectF circleBounds;
 
@@ -139,6 +141,7 @@ private void init(@NonNull Context context, @Nullable AttributeSet attrs) {
         int textSize = sp2px(DEFAULT_TEXT_SIZE_SP);
 
         shouldDrawDot = true;
+
         int dotColor = progressColor;
         int dotWidth = progressStrokeWidth;
 
@@ -155,6 +158,7 @@ private void init(@NonNull Context context, @Nullable AttributeSet attrs) {
             textSize = a.getDimensionPixelSize(R.styleable.CircularProgressIndicator_textSize, textSize);
 
             shouldDrawDot = a.getBoolean(R.styleable.CircularProgressIndicator_drawDot, true);
+            dotAnglePosition = a.getInt(R.styleable.CircularProgressIndicator_dotAnglePosition, DEFAULT_DOT_ANGLE_POSITION);
             dotColor = a.getColor(R.styleable.CircularProgressIndicator_dotColor, progressColor);
             dotWidth = a.getDimensionPixelSize(R.styleable.CircularProgressIndicator_dotWidth, progressStrokeWidth);
 
@@ -348,9 +352,18 @@ private void drawProgress(Canvas canvas) {
     }
 
     private void drawDot(Canvas canvas) {
-        double angleRadians = Math.toRadians(startAngle + sweepAngle + 180);
+
+        double angleRadians;
+
+        if(startAngle != DEFAULT_DOT_ANGLE_POSITION){
+            angleRadians = Math.toRadians(dotAnglePosition + 180);
+        }else{
+            angleRadians = Math.toRadians(startAngle + sweepAngle + 180);
+        }
+
         float cos = (float) Math.cos(angleRadians);
         float sin = (float) Math.sin(angleRadians);
+
         float x = circleBounds.centerX() - radius * cos;
         float y = circleBounds.centerY() - radius * sin;
 
@@ -639,6 +652,11 @@ public void setStartAngle(@IntRange(from = 0, to = 360) int startAngle) {
         invalidate();
     }
 
+    public void setDotAnglePosition(@IntRange(from = 0, to = 360) int dotAnglePosition){
+        this.dotAnglePosition = dotAnglePosition;
+        invalidate();
+    }
+
     @Direction
     public int getDirection() {
         return direction;

circularprogressindicator/src/main/res/values/attrs.xml

@@ -17,6 +17,7 @@
         <attr name="dotWidth" format="dimension" />
 
         <attr name="startAngle" format="integer|reference" />
+        <attr name="dotAnglePosition" format="integer|reference"/>
 
         <attr name="direction" format="enum">
             <enum name="clockwise" value="0" />

example/src/main/java/antonkozyriatskyi/circularprogressindicatorexample/MainActivity.java

@@ -26,6 +26,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
 
     private Button dotColor;
     private SeekBar dotWidth;
+    private SeekBar dotPositionSeekBar;
 
     private CircularProgressIndicator circularProgress;
 
@@ -53,6 +54,10 @@ protected void onCreate(Bundle savedInstanceState) {
         SeekBar textSize = findViewById(R.id.sb_text_size);
         dotWidth = findViewById(R.id.sb_dot_width);
 
+        dotPositionSeekBar = findViewById(R.id.sb_dot_position);
+        dotPositionSeekBar.setOnSeekBarChangeListener(this);
+        dotPositionSeekBar.setEnabled(false);//default to disabled since we cannot disable via xml
+
         progress.setOnSeekBarChangeListener(this);
         progressStrokeWidth.setOnSeekBarChangeListener(this);
         progressBackgroundStrokeWidth.setOnSeekBarChangeListener(this);
@@ -83,6 +88,14 @@ public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
             }
         });
 
+        final CheckBox dotPosition = findViewById(R.id.cb_dot_position);
+        dotPosition.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                dotPositionSeekBar.setEnabled(isChecked);
+            }
+        });
+
         RadioGroup progressCap = findViewById(R.id.rg_cap);
         progressCap.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
             @Override
@@ -199,6 +212,9 @@ public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
             case R.id.sb_progress_background_width:
                 circularProgress.setProgressBackgroundStrokeWidthDp(progress);
                 break;
+            case R.id.sb_dot_position:
+                circularProgress.setDotAnglePosition(progress);
+                break;
         }
     }
 

example/src/main/res/layout/activity_main.xml

@@ -111,6 +111,14 @@
                 android:layout_marginLeft="8dp"
                 android:text="Fill background" />
 
+            <CheckBox
+                android:id="@+id/cb_dot_position"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginLeft="8dp"
+                android:text="Static dot position"/>
+
+
             <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
@@ -126,6 +134,19 @@
                 android:min="0"
                 android:progress="8" />
 
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="Progress dot position angle"/>
+
+            <SeekBar
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:max="360"
+                android:min="0"
+                android:layout_marginTop="8dp"
+                android:id="@+id/sb_dot_position"/>
+
             <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"