VerticalHandleHelper.java

/*
 * Copyright 2013, Edmodo, Inc. 
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License.
 * You may obtain a copy of the License in the LICENSE file, or at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" 
 * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language 
 * governing permissions and limitations under the License. 
 */

package com.smartandroid.sa.cropper;

import android.graphics.Rect;

/**
 * HandleHelper class to handle vertical handles (i.e. left and right handles).
 */
class VerticalHandleHelper extends HandleHelper {

	// Member Variables ////////////////////////////////////////////////////////

	private Edge mEdge;

	// Constructor /////////////////////////////////////////////////////////////

	VerticalHandleHelper(Edge edge) {
		super(null, edge);
		mEdge = edge;
	}

	// HandleHelper Methods ////////////////////////////////////////////////////

	@Override
	void updateCropWindow(float x, float y, float targetAspectRatio,
			Rect imageRect, float snapRadius) {

		// Adjust this Edge accordingly.
		mEdge.adjustCoordinate(x, y, imageRect, snapRadius, targetAspectRatio);

		float left = Edge.LEFT.getCoordinate();
		float top = Edge.TOP.getCoordinate();
		float right = Edge.RIGHT.getCoordinate();
		float bottom = Edge.BOTTOM.getCoordinate();

		// After this Edge is moved, our crop window is now out of proportion.
		final float targetHeight = AspectRatioUtil.calculateHeight(left, right,
				targetAspectRatio);
		final float currentHeight = bottom - top;

		// Adjust the crop window so that it maintains the given aspect ratio by
		// moving the adjacent edges symmetrically in or out.
		final float difference = targetHeight - currentHeight;
		final float halfDifference = difference / 2;
		top -= halfDifference;
		bottom += halfDifference;

		Edge.TOP.setCoordinate(top);
		Edge.BOTTOM.setCoordinate(bottom);

		// Check if we have gone out of bounds on the top or bottom, and fix.
		if (Edge.TOP.isOutsideMargin(imageRect, snapRadius)
				&& !mEdge.isNewRectangleOutOfBounds(Edge.TOP, imageRect,
						targetAspectRatio)) {
			final float offset = Edge.TOP.snapToRect(imageRect);
			Edge.BOTTOM.offset(-offset);
			mEdge.adjustCoordinate(targetAspectRatio);
		}
		if (Edge.BOTTOM.isOutsideMargin(imageRect, snapRadius)
				&& !mEdge.isNewRectangleOutOfBounds(Edge.BOTTOM, imageRect,
						targetAspectRatio)) {
			final float offset = Edge.BOTTOM.snapToRect(imageRect);
			Edge.TOP.offset(-offset);
			mEdge.adjustCoordinate(targetAspectRatio);
		}
	}
}