/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License 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.android.gallery3d.photoeditor.actions;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import com.android.gallery3d.R;
/**
* A view that tracks touch motions and adjusts crop bounds accordingly.
*/
class CropView extends FullscreenToolView {
/**
* Listener of crop bounds.
*/
public interface OnCropChangeListener {
void onCropChanged(RectF cropBounds, boolean fromUser);
}
private static final int MOVE_LEFT = 1;
private static final int MOVE_TOP = 2;
private static final int MOVE_RIGHT = 4;
private static final int MOVE_BOTTOM = 8;
private static final int MOVE_BLOCK = 16;
private static final int MIN_CROP_WIDTH_HEIGHT = 2;
private static final int TOUCH_TOLERANCE = 25;
private static final int SHADOW_ALPHA = 160;
private final Paint borderPaint;
private final Drawable cropIndicator;
private final int indicatorSize;
private final RectF cropBounds = new RectF(0, 0, 1, 1);
private float lastX;
private float lastY;
private int movingEdges;
private OnCropChangeListener listener;
public CropView(Context context, AttributeSet attrs) {
super(context, attrs);
Resources resources = context.getResources();
cropIndicator = resources.getDrawable(R.drawable.camera_crop_holo);
indicatorSize = (int) resources.getDimension(R.dimen.crop_indicator_size);
int borderColor = resources.getColor(R.color.opaque_cyan);
borderPaint = new Paint();
borderPaint.setStyle(Paint.Style.STROKE);
borderPaint.setColor(borderColor);
borderPaint.setStrokeWidth(2f);
}
public void setOnCropChangeListener(OnCropChangeListener listener) {
this.listener = listener;
}
private void refreshByCropChange(boolean fromUser) {
if (listener != null) {
listener.onCropChanged(new RectF(cropBounds), fromUser);
}
invalidate();
}
/**
* Sets cropped bounds; modifies the bounds if it's smaller than the allowed dimensions.
*/
public void setCropBounds(RectF bounds) {
// Avoid cropping smaller than minimum width or height.
if (bounds.width() * getPhotoWidth() < MIN_CROP_WIDTH_HEIGHT) {
bounds.set(0, bounds.top, 1, bounds.bottom);
}
if (bounds.height() * getPhotoHeight() < MIN_CROP_WIDTH_HEIGHT) {
bounds.set(bounds.left, 0, bounds.right, 1);
}
cropBounds.set(bounds);
refreshByCropChange(false);
}
private RectF getCropBoundsDisplayed() {
float width = displayBounds.width();
float height = displayBounds.height();
RectF cropped = new RectF(cropBounds.left * width, cropBounds.top * height,
cropBounds.right * width, cropBounds.bottom * height);
cropped.offset(displayBounds.left, displayBounds.top);
return cropped;
}
private void detectMovingEdges(float x, float y) {
RectF cropped = getCropBoundsDisplayed();
movingEdges = 0;
// Check left or right.
float left = Math.abs(x - cropped.left);
float right = Math.abs(x - cropped.right);
if ((left <= TOUCH_TOLERANCE) && (left < right)) {
movingEdges |= MOVE_LEFT;
}
else if (right <= TOUCH_TOLERANCE) {
movingEdges |= MOVE_RIGHT;
}
// Check top or bottom.
float top = Math.abs(y - cropped.top);
float bottom = Math.abs(y - cropped.bottom);
if ((top <= TOUCH_TOLERANCE) & (top < bottom)) {
movingEdges |= MOVE_TOP;
}
else if (bottom <= TOUCH_TOLERANCE) {
movingEdges |= MOVE_BOTTOM;
}
// Check inside block.
if (cropped.contains(x, y) && (movingEdges == 0)) {
movingEdges = MOVE_BLOCK;
}
invalidate();
}
private void moveEdges(float deltaX, float deltaY) {
RectF cropped = getCropBoundsDisplayed();
if (movingEdges == MOVE_BLOCK) {
// Move the whole cropped bounds within the photo display bounds.
deltaX = (deltaX > 0) ? Math.min(displayBounds.right - cropped.right, deltaX)
: Math.max(displayBounds.left - cropped.left, deltaX);
deltaY = (deltaY > 0) ? Math.min(displayBounds.bottom - cropped.bottom, deltaY)
: Math.max(displayBounds.top - cropped.top, deltaY);
cropped.offset(deltaX, deltaY);
} else {
// Adjust cropped bound dimensions within the photo display bounds.
float minWidth = MIN_CROP_WIDTH_HEIGHT * displayBounds.width() / getPhotoWidth();
float minHeight = MIN_CROP_WIDTH_HEIGHT * displayBounds.height() / getPhotoHeight();
if ((movingEdges & MOVE_LEFT) != 0) {
cropped.left = Math.min(cropped.left + deltaX, cropped.right - minWidth);
}
if ((movingEdges & MOVE_TOP) != 0) {
cropped.top = Math.min(cropped.top + deltaY, cropped.bottom - minHeight);
}
if ((movingEdges & MOVE_RIGHT) != 0) {
cropped.right = Math.max(cropped.right + deltaX, cropped.left + minWidth);
}
if ((movingEdges & MOVE_BOTTOM) != 0) {
cropped.bottom = Math.max(cropped.bottom + deltaY, cropped.top + minHeight);
}
cropped.intersect(displayBounds);
}
mapPhotoRect(cropped, cropBounds);
refreshByCropChange(true);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
if (isEnabled()) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
detectMovingEdges(x, y);
lastX = x;
lastY = y;
break;
case MotionEvent.ACTION_MOVE:
if (movingEdges != 0) {
moveEdges(x - lastX, y - lastY);
}
lastX = x;
lastY = y;
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
movingEdges = 0;
invalidate();
break;
}
}
return true;
}
private void drawIndicator(Canvas canvas, Drawable indicator, float centerX, float centerY) {
int left = (int) centerX - indicatorSize / 2;
int top = (int) centerY - indicatorSize / 2;
indicator.setBounds(left, top, left + indicatorSize, top + indicatorSize);
indicator.draw(canvas);
}
private void drawShadow(Canvas canvas, float left, float top, float right, float bottom) {
canvas.save();
canvas.clipRect(left, top, right, bottom);
canvas.drawARGB(SHADOW_ALPHA, 0, 0, 0);
canvas.restore();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Draw shadow on non-cropped bounds and the border around cropped bounds.
RectF cropped = getCropBoundsDisplayed();
drawShadow(canvas, displayBounds.left, displayBounds.top, displayBounds.right, cropped.top);
drawShadow(canvas, displayBounds.left, cropped.top, cropped.left, displayBounds.bottom);
drawShadow(canvas, cropped.right, cropped.top, displayBounds.right, displayBounds.bottom);
drawShadow(canvas, cropped.left, cropped.bottom, cropped.right, displayBounds.bottom);
canvas.drawRect(cropped, borderPaint);
boolean notMoving = movingEdges == 0;
if (((movingEdges & MOVE_TOP) != 0) || notMoving) {
drawIndicator(canvas, cropIndicator, cropped.centerX(), cropped.top);
}
if (((movingEdges & MOVE_BOTTOM) != 0) || notMoving) {
drawIndicator(canvas, cropIndicator, cropped.centerX(), cropped.bottom);
}
if (((movingEdges & MOVE_LEFT) != 0) || notMoving) {
drawIndicator(canvas, cropIndicator, cropped.left, cropped.centerY());
}
if (((movingEdges & MOVE_RIGHT) != 0) || notMoving) {
drawIndicator(canvas, cropIndicator, cropped.right, cropped.centerY());
}
}
}