Add ClipRectActivity

Author: chiuki

app/src/main/AndroidManifest.xml

@@ -27,6 +27,10 @@
         android:name=".PeekThroughActivity"
         android:label="@string/peek_through"
         android:parentActivityName=".MainActivity" />
+    <activity
+      android:name=".ClipRectActivity"
+      android:label="@string/clip_rect"
+      android:parentActivityName=".MainActivity" />
     <activity
         android:name=".ColorMatrixActivity"
         android:label="@string/color_matrix"

app/src/main/java/com/sqisland/android/graphics_demo/ClipRectActivity.java

@@ -0,0 +1,47 @@
+package com.sqisland.android.graphics_demo;
+
+import android.app.Activity;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.os.Bundle;
+import android.widget.ImageView;
+
+public class ClipRectActivity extends Activity {
+  private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+  private RectF rect = new RectF();
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_clip_rect);
+
+    ImageView imageView = (ImageView) findViewById(R.id.image);
+    int width = getResources().getDimensionPixelSize(R.dimen.clip_rect_width);
+    int height = getResources().getDimensionPixelSize(R.dimen.clip_rect_height);
+
+    Bitmap bitmap = createClipRect(width, height);
+    imageView.setImageBitmap(bitmap);
+  }
+
+  // Assumes width > height
+  private Bitmap createClipRect(int width, int height) {
+    paint.setColor(Color.GREEN);
+
+    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+    Canvas canvas = new Canvas(bitmap);
+    float radius = height / 2;
+
+    canvas.save();
+    canvas.clipRect(0, 0, width, height);
+
+    rect.set(0, 0, width + height, height);
+    canvas.drawRoundRect(rect, radius, radius, paint);
+
+    canvas.restore();
+
+    return bitmap;
+  }
+}

app/src/main/java/com/sqisland/android/graphics_demo/MainActivity.java

@@ -27,6 +27,7 @@ protected void onCreate(Bundle savedInstanceState) {
     demos.add(new Demo(this, RainbowGradientActivity.class, R.string.rainbow_gradient));
     demos.add(new Demo(this, PatternedTextActivity.class, R.string.patterned_text));
     demos.add(new Demo(this, PeekThroughActivity.class, R.string.peek_through));
+    demos.add(new Demo(this, ClipRectActivity.class, R.string.clip_rect));
     demos.add(new Demo(this, ColorMatrixActivity.class, R.string.color_matrix));
     demos.add(new Demo(this, FourColorsActivity.class, R.string.four_colors));
     demos.add(new Demo(this, PorterDuffActivity.class, R.string.porter_duff));

app/src/main/res/layout/activity_clip_rect.xml

@@ -0,0 +1,8 @@
+<ImageView
+  xmlns:android="http://schemas.android.com/apk/res/android"
+  xmlns:tools="http://schemas.android.com/tools"
+  android:id="@+id/image"
+  android:layout_width="wrap_content"
+  android:layout_height="wrap_content"
+  android:layout_gravity="center"
+  tools:context=".ClipRectActivity"/>

app/src/main/res/values/dimens.xml

@@ -8,4 +8,7 @@
   <dimen name="peek_through_radius">40dp</dimen>
 
   <dimen name="dashed_text_stroke_width">8dp</dimen>
+
+  <dimen name="clip_rect_width">120dp</dimen>
+  <dimen name="clip_rect_height">40dp</dimen>
 </resources>

app/src/main/res/values/strings.xml

@@ -12,6 +12,8 @@
   <string name="peek_through">Peek through</string>
   <string name="peek_through_help">Touch the gray area to peek</string>
 
+  <string name="clip_rect">Clip rect</string>
+
   <string name="color_matrix">ColorMatrix</string>
   <string name="grayscale">Grayscale</string>
   <string name="sepia">Sepia</string>