private void drawBackground(Canvas canvas, Rect bitmapRect) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
/*-
-------------------------------------
| top |
-------------------------------------
| | | |
| | | |
| left | | right |
| | | |
| | | |
-------------------------------------
| bottom |
-------------------------------------
*/
// Draw "top", "bottom", "left", then "right" quadrants.
canvas.drawRect(bitmapRect.left, bitmapRect.top, bitmapRect.right, top, mBackgroundPaint);
canvas.drawRect(bitmapRect.left, bottom, bitmapRect.right, bitmapRect.bottom, mBackgroundPaint);
canvas.drawRect(bitmapRect.left, top, left, bottom, mBackgroundPaint);
canvas.drawRect(right, top, bitmapRect.right, bottom, mBackgroundPaint);
}
/**
* Indicates whether the crop window is small enough that the guidelines should be shown. Public
* because this function is also used to determine if the center handle should be focused.
*
* @return boolean Whether the guidelines should be shown or not
*/
public static boolean showGuidelines() {
if ((Math.abs(Edge.LEFT.getCoordinate() - Edge.RIGHT.getCoordinate())
< DEFAULT_SHOW_GUIDELINES_LIMIT)
|| (Math.abs(Edge.TOP.getCoordinate() - Edge.BOTTOM.getCoordinate())
< DEFAULT_SHOW_GUIDELINES_LIMIT)) return false;
else return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Draw translucent background for the cropped area.
drawBackground(canvas, mBitmapRect);
if (showGuidelines()) {
// Determines whether guidelines should be drawn or not
if (mGuidelines == GUIDELINES_ON) {
drawRuleOfThirdsGuidelines(canvas);
} else if (mGuidelines == GUIDELINES_ON_TOUCH) {
// Draw only when resizing
if (mPressedHandle != null) drawRuleOfThirdsGuidelines(canvas);
} else if (mGuidelines == GUIDELINES_OFF) {
// Do nothing
}
}
// Draws the main crop window border.
canvas.drawRect(
Edge.LEFT.getCoordinate(),
Edge.TOP.getCoordinate(),
Edge.RIGHT.getCoordinate(),
Edge.BOTTOM.getCoordinate(),
mBorderPaint);
// Draws the corners
drawCorners(canvas);
}
private void drawCorners(Canvas canvas) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
// Draws the corner lines
// Top left
canvas.drawLine(
left - mCornerOffset,
top - mCornerExtension,
left - mCornerOffset,
top + mCornerLength,
mCornerPaint);
canvas.drawLine(
left, top - mCornerOffset, left + mCornerLength, top - mCornerOffset, mCornerPaint);
// Top right
canvas.drawLine(
right + mCornerOffset,
top - mCornerExtension,
right + mCornerOffset,
top + mCornerLength,
mCornerPaint);
canvas.drawLine(
right, top - mCornerOffset, right - mCornerLength, top - mCornerOffset, mCornerPaint);
// Bottom left
canvas.drawLine(
left - mCornerOffset,
bottom + mCornerExtension,
left - mCornerOffset,
bottom - mCornerLength,
mCornerPaint);
canvas.drawLine(
left, bottom + mCornerOffset, left + mCornerLength, bottom + mCornerOffset, mCornerPaint);
// Bottom left
canvas.drawLine(
right + mCornerOffset,
bottom + mCornerExtension,
right + mCornerOffset,
bottom - mCornerLength,
mCornerPaint);
canvas.drawLine(
right, bottom + mCornerOffset, right - mCornerLength, bottom + mCornerOffset, mCornerPaint);
}
/**
* Handles a {@link MotionEvent#ACTION_DOWN} event.
*
* @param x the x-coordinate of the down action
* @param y the y-coordinate of the down action
*/
private void onActionDown(float x, float y) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
mPressedHandle = HandleUtil.getPressedHandle(x, y, left, top, right, bottom, mHandleRadius);
if (mPressedHandle == null) return;
// Calculate the offset of the touch point from the precise location
// of the handle. Save these values in a member variable since we want
// to maintain this offset as we drag the handle.
mTouchOffset = HandleUtil.getOffset(mPressedHandle, x, y, left, top, right, bottom);
invalidate();
}
private void drawRuleOfThirdsGuidelines(Canvas canvas) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
// Draw vertical guidelines.
final float oneThirdCropWidth = Edge.getWidth() / 3;
final float x1 = left + oneThirdCropWidth;
canvas.drawLine(x1, top, x1, bottom, mGuidelinePaint);
final float x2 = right - oneThirdCropWidth;
canvas.drawLine(x2, top, x2, bottom, mGuidelinePaint);
// Draw horizontal guidelines.
final float oneThirdCropHeight = Edge.getHeight() / 3;
final float y1 = top + oneThirdCropHeight;
canvas.drawLine(left, y1, right, y1, mGuidelinePaint);
final float y2 = bottom - oneThirdCropHeight;
canvas.drawLine(left, y2, right, y2, mGuidelinePaint);
}
/**
* Set the initial crop window size and position. This is dependent on the size and position of
* the image being cropped.
*
* @param bitmapRect the bounding box around the image being cropped
*/
private void initCropWindow(Rect bitmapRect) {
// Tells the attribute functions the crop window has already been
// initialized
if (initializedCropWindow == false) initializedCropWindow = true;
if (mFixAspectRatio) {
// If the image aspect ratio is wider than the crop aspect ratio,
// then the image height is the determining initial length. Else,
// vice-versa.
if (AspectRatioUtil.calculateAspectRatio(bitmapRect) > mTargetAspectRatio) {
Edge.TOP.setCoordinate(bitmapRect.top);
Edge.BOTTOM.setCoordinate(bitmapRect.bottom);
final float centerX = getWidth() / 2f;
// Limits the aspect ratio to no less than 40 wide or 40 tall
final float cropWidth =
Math.max(
Edge.MIN_CROP_LENGTH_PX,
AspectRatioUtil.calculateWidth(
Edge.TOP.getCoordinate(), Edge.BOTTOM.getCoordinate(), mTargetAspectRatio));
// Create new TargetAspectRatio if the original one does not fit
// the screen
if (cropWidth == Edge.MIN_CROP_LENGTH_PX)
mTargetAspectRatio =
(Edge.MIN_CROP_LENGTH_PX) / (Edge.BOTTOM.getCoordinate() - Edge.TOP.getCoordinate());
final float halfCropWidth = cropWidth / 2f;
Edge.LEFT.setCoordinate(centerX - halfCropWidth);
Edge.RIGHT.setCoordinate(centerX + halfCropWidth);
} else {
Edge.LEFT.setCoordinate(bitmapRect.left);
Edge.RIGHT.setCoordinate(bitmapRect.right);
final float centerY = getHeight() / 2f;
// Limits the aspect ratio to no less than 40 wide or 40 tall
final float cropHeight =
Math.max(
Edge.MIN_CROP_LENGTH_PX,
AspectRatioUtil.calculateHeight(
Edge.LEFT.getCoordinate(), Edge.RIGHT.getCoordinate(), mTargetAspectRatio));
// Create new TargetAspectRatio if the original one does not fit
// the screen
if (cropHeight == Edge.MIN_CROP_LENGTH_PX)
mTargetAspectRatio =
(Edge.RIGHT.getCoordinate() - Edge.LEFT.getCoordinate()) / Edge.MIN_CROP_LENGTH_PX;
final float halfCropHeight = cropHeight / 2f;
Edge.TOP.setCoordinate(centerY - halfCropHeight);
Edge.BOTTOM.setCoordinate(centerY + halfCropHeight);
}
} else { // ... do not fix aspect ratio...
// Initialize crop window to have 10% padding w/ respect to image.
final float horizontalPadding = 0.1f * bitmapRect.width();
final float verticalPadding = 0.1f * bitmapRect.height();
Edge.LEFT.setCoordinate(bitmapRect.left + horizontalPadding);
Edge.TOP.setCoordinate(bitmapRect.top + verticalPadding);
Edge.RIGHT.setCoordinate(bitmapRect.right - horizontalPadding);
Edge.BOTTOM.setCoordinate(bitmapRect.bottom - verticalPadding);
}
}