How to use

ShadowCanvas

in

org.robolectric.shadows

/**
 * Returns a textual representation of the appearance of the object.
 *
 * @param canvas the canvas to visualize
 * @return The textual representation of the appearance of the object.
 */
public static String visualize(Canvas canvas) {
 ShadowCanvas shadowCanvas = Shadow.extract(canvas);
 return shadowCanvas.getDescription();
}

@Test
public void resetCanvasHistory_shouldClearTheHistoryAndDescription() throws Exception {
 Canvas canvas = new Canvas();
 canvas.drawPath(new Path(), new Paint());
 canvas.drawText("hi", 1, 2, new Paint());
 ShadowCanvas shadow = shadowOf(canvas);
 shadow.resetCanvasHistory();
 assertThat(shadow.getPathPaintHistoryCount()).isEqualTo(0);
 assertThat(shadow.getTextHistoryCount()).isEqualTo(0);
 assertEquals("", shadow.getDescription());
}

@Implementation
protected void drawBitmap(Bitmap bitmap, float left, float top, Paint paint) {
 describeBitmap(bitmap, paint);
 int x = (int) (left + translateX);
 int y = (int) (top + translateY);
 if (x != 0 || y != 0) {
  appendDescription(" at (" + x + "," + y + ")");
}
 if (scaleX != 1 && scaleY != 1) {
  appendDescription(" scaled by (" + scaleX + "," + scaleY + ")");
 }
}

private void separateLines() {
 if (getDescription().length() != 0) {
  appendDescription("\n");
 }
}

@Implementation
protected void drawPath(Path path, Paint paint) {
 pathPaintEvents.add(new PathPaintHistoryEvent(new Path(path), new Paint(paint)));
 separateLines();
 ShadowPath shadowPath = Shadow.extract(path);
 appendDescription("Path " + shadowPath.getPoints().toString());
}

private void describeBitmap(Bitmap bitmap, Paint paint) {
 separateLines();
 ShadowBitmap shadowBitmap = Shadow.extract(bitmap);
 appendDescription(shadowBitmap.getDescription());
 if (paint != null) {
  ColorFilter colorFilter = paint.getColorFilter();
  if (colorFilter != null) {
   if (colorFilter instanceof ColorMatrixColorFilter) {
    ColorMatrixColorFilter colorMatrixColorFilter = (ColorMatrixColorFilter) colorFilter;
    ShadowColorMatrixColorFilter shadowColorMatrixColorFilter =
      Shadow.extract(colorMatrixColorFilter);
    ColorMatrix colorMatrix = shadowColorMatrixColorFilter.getMatrix();
    appendDescription(" with ColorMatrixColorFilter<" + formatColorMatric(colorMatrix) + ">");
   } else {
    appendDescription(" with " + colorFilter);
   }
  }
 }
}

@Implementation
protected void drawColor(int color) {
 appendDescription("draw color " + color);
}

public boolean hasDrawnPath() {
 return getPathPaintHistoryCount() > 0;
}

@Test
public void drawPath_shouldRecordThePathAndThePaint() throws Exception {
 Canvas canvas = new Canvas(targetBitmap);
 Path path = new Path();
 path.lineTo(10, 10);
 Paint paint = new Paint();
 paint.setColor(Color.RED);
 paint.setAlpha(7);
 canvas.drawPath(path, paint);
 // changing the values on this Paint shouldn't affect recorded painted path
 paint.setColor(Color.BLUE);
 paint.setAlpha(8);
 ShadowCanvas shadow = shadowOf(canvas);
 assertThat(shadow.getPathPaintHistoryCount()).isEqualTo(1);
 ShadowPath drawnPath = shadowOf(shadow.getDrawnPath(0));
 assertEquals(drawnPath.getPoints().get(0), new ShadowPath.Point(10, 10, LINE_TO));
 Paint drawnPathPaint = shadow.getDrawnPathPaint(0);
 assertThat(drawnPathPaint.getColor()).isEqualTo(Color.RED);
 assertThat(drawnPathPaint.getAlpha()).isEqualTo(7);
}

@Test
public void drawPath_shouldRecordThePointsOfEachPathEvenWhenItIsTheSameInstance() throws Exception {
 Canvas canvas = new Canvas(targetBitmap);
 Paint paint = new Paint();
 Path path = new Path();
 path.lineTo(10, 10);
 canvas.drawPath(path, paint);
 path.reset();
 path.lineTo(20, 20);
 canvas.drawPath(path, paint);
 ShadowCanvas shadow = shadowOf(canvas);
 assertThat(shadow.getPathPaintHistoryCount()).isEqualTo(2);
 assertEquals(shadowOf(shadow.getDrawnPath(0)).getPoints().get(0), new ShadowPath.Point(10, 10, LINE_TO));
 assertEquals(shadowOf(shadow.getDrawnPath(1)).getPoints().get(0), new ShadowPath.Point(20, 20, LINE_TO));
}

private void describeBitmap(Bitmap bitmap, Paint paint) {
 separateLines();
 appendDescription(shadowOf(bitmap).getDescription());
 if (paint != null) {
  ColorFilter colorFilter = paint.getColorFilter();
  if (colorFilter != null) {
   appendDescription(" with " + colorFilter);
  }
 }
}

private void separateLines() {
 if (getDescription().length() != 0) {
  appendDescription("\n");
 }
}

private void describeBitmap(Bitmap bitmap, Paint paint) {
 separateLines();
 ShadowBitmap shadowBitmap = Shadow.extract(bitmap);
 appendDescription(shadowBitmap.getDescription());
 if (paint != null) {
  ColorFilter colorFilter = paint.getColorFilter();
  if (colorFilter != null) {
   if (colorFilter instanceof ColorMatrixColorFilter) {
    ColorMatrixColorFilter colorMatrixColorFilter = (ColorMatrixColorFilter) colorFilter;
    ShadowColorMatrixColorFilter shadowColorMatrixColorFilter =
      Shadow.extract(colorMatrixColorFilter);
    ColorMatrix colorMatrix = shadowColorMatrixColorFilter.getMatrix();
    appendDescription(" with ColorMatrixColorFilter<" + formatColorMatric(colorMatrix) + ">");
   } else {
    appendDescription(" with " + colorFilter);
   }
  }
 }
}

@Implementation
protected void draw(android.graphics.Canvas canvas) {
 Drawable background = realView.getBackground();
 if (background != null) {
  ShadowCanvas shadowCanvas = Shadow.extract(canvas);
  shadowCanvas.appendDescription("background:");
  background.draw(canvas);
 }
}

public boolean hasDrawnPath() {
 return getPathPaintHistoryCount() > 0;
}

@Implementation
protected void drawBitmap(Bitmap bitmap, Rect src, Rect dst, Paint paint) {
 describeBitmap(bitmap, paint);
 StringBuilder descriptionBuilder = new StringBuilder();
 if (dst != null) {
  descriptionBuilder.append(" at (").append(dst.left).append(",").append(dst.top)
    .append(") with height=").append(dst.height()).append(" and width=").append(dst.width());
 }
 if (src != null) {
  descriptionBuilder.append( " taken from ").append(src.toString());
 }
 appendDescription(descriptionBuilder.toString());
}

/**
 * Returns a textual representation of the appearance of the object.
 *
 * @param view the view to visualize
 * @return Textual representation of the appearance of the object.
 */
public static String visualize(View view) {
 Canvas canvas = new Canvas();
 view.draw(canvas);
 ShadowCanvas shadowCanvas = Shadow.extract(canvas);
 return shadowCanvas.getDescription();
}

private void describeBitmap(Bitmap bitmap, Paint paint) {
 separateLines();
 appendDescription(shadowOf(bitmap).getDescription());
 if (paint != null) {
  ColorFilter colorFilter = paint.getColorFilter();
  if (colorFilter != null) {
   appendDescription(" with " + colorFilter);
  }
 }
}

private void separateLines() {
 if (getDescription().length() != 0) {
  appendDescription("\n");
 }
}

@Implementation
public void drawColor(int color) {
 appendDescription("draw color " + color);
}