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Apache License
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/* * Copyright 2013, Edmodo, Inc. // w w w .j a va 2 s . c o m * * 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.edmodo.cropper.cropwindow.handle; import android.graphics.Rect; import com.edmodo.cropper.cropwindow.edge.Edge; import com.edmodo.cropper.cropwindow.edge.EdgePair; import com.edmodo.cropper.util.AspectRatioUtil; /** * Abstract helper class to handle operations on a crop window Handle. */ abstract class HandleHelper { // Member Variables //////////////////////////////////////////////////////// private static final float UNFIXED_ASPECT_RATIO_CONSTANT = 1; private Edge mHorizontalEdge; private Edge mVerticalEdge; // Save the Pair object as a member variable to avoid having to instantiate // a new Object every time getActiveEdges() is called. private EdgePair mActiveEdges; // Constructor ///////////////////////////////////////////////////////////// /** * Constructor. * * @param horizontalEdge the horizontal edge associated with this handle; * may be null * @param verticalEdge the vertical edge associated with this handle; may be * null */ HandleHelper(Edge horizontalEdge, Edge verticalEdge) { mHorizontalEdge = horizontalEdge; mVerticalEdge = verticalEdge; mActiveEdges = new EdgePair(mHorizontalEdge, mVerticalEdge); } // Package-Private Methods ///////////////////////////////////////////////// /** * Updates the crop window by directly setting the Edge coordinates. * * @param x the new x-coordinate of this handle * @param y the new y-coordinate of this handle * @param imageRect the bounding rectangle of the image * @param parentView the parent View containing the image * @param snapRadius the maximum distance (in pixels) at which the crop * window should snap to the image */ void updateCropWindow(float x, float y, Rect imageRect, float snapRadius) { final EdgePair activeEdges = getActiveEdges(); final Edge primaryEdge = activeEdges.primary; final Edge secondaryEdge = activeEdges.secondary; if (primaryEdge != null) primaryEdge.adjustCoordinate(x, y, imageRect, snapRadius, UNFIXED_ASPECT_RATIO_CONSTANT); if (secondaryEdge != null) secondaryEdge.adjustCoordinate(x, y, imageRect, snapRadius, UNFIXED_ASPECT_RATIO_CONSTANT); } /** * Updates the crop window by directly setting the Edge coordinates; this * method maintains a given aspect ratio. * * @param x the new x-coordinate of this handle * @param y the new y-coordinate of this handle * @param targetAspectRatio the aspect ratio to maintain * @param imageRect the bounding rectangle of the image * @param parentView the parent View containing the image * @param snapRadius the maximum distance (in pixels) at which the crop * window should snap to the image */ abstract void updateCropWindow(float x, float y, float targetAspectRatio, Rect imageRect, float snapRadius); /** * Gets the Edges associated with this handle (i.e. the Edges that should be * moved when this handle is dragged). This is used when we are not * maintaining the aspect ratio. * * @return the active edge as a pair (the pair may contain null values for * the <code>primary</code>, <code>secondary</code> or both fields) */ EdgePair getActiveEdges() { return mActiveEdges; } /** * Gets the Edges associated with this handle as an ordered Pair. The * <code>primary</code> Edge in the pair is the determining side. This * method is used when we need to maintain the aspect ratio. * * @param x the x-coordinate of the touch point * @param y the y-coordinate of the touch point * @param targetAspectRatio the aspect ratio that we are maintaining * @return the active edges as an ordered pair */ EdgePair getActiveEdges(float x, float y, float targetAspectRatio) { // Calculate the aspect ratio if this handle were dragged to the given // x-y coordinate. final float potentialAspectRatio = getAspectRatio(x, y); // If the touched point is wider than the aspect ratio, then x // is the determining side. Else, y is the determining side. if (potentialAspectRatio > targetAspectRatio) { mActiveEdges.primary = mVerticalEdge; mActiveEdges.secondary = mHorizontalEdge; } else { mActiveEdges.primary = mHorizontalEdge; mActiveEdges.secondary = mVerticalEdge; } return mActiveEdges; } // Private Methods ///////////////////////////////////////////////////////// /** * Gets the aspect ratio of the resulting crop window if this handle were * dragged to the given point. * * @param x the x-coordinate * @param y the y-coordinate * @return the aspect ratio */ private float getAspectRatio(float x, float y) { // Replace the active edge coordinate with the given touch coordinate. final float left = (mVerticalEdge == Edge.LEFT) ? x : Edge.LEFT.getCoordinate(); final float top = (mHorizontalEdge == Edge.TOP) ? y : Edge.TOP.getCoordinate(); final float right = (mVerticalEdge == Edge.RIGHT) ? x : Edge.RIGHT.getCoordinate(); final float bottom = (mHorizontalEdge == Edge.BOTTOM) ? y : Edge.BOTTOM.getCoordinate(); final float aspectRatio = AspectRatioUtil.calculateAspectRatio(left, top, right, bottom); return aspectRatio; } }