/*
* Copyright (C) 2011 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.ui;
import android.content.Context;
import android.opengl.Matrix;
import com.android.gallery3d.glrenderer.GLCanvas;
// EdgeView draws EdgeEffect (blue glow) at four sides of the view.
public class EdgeView extends GLView {
@SuppressWarnings("unused")
private static final String TAG = "EdgeView";
public static final int INVALID_DIRECTION = -1;
public static final int TOP = 0;
public static final int LEFT = 1;
public static final int BOTTOM = 2;
public static final int RIGHT = 3;
// Each edge effect has a transform matrix, and each matrix has 16 elements.
// We put all the elements in one array. These constants specify the
// starting index of each matrix.
private static final int TOP_M = TOP * 16;
private static final int LEFT_M = LEFT * 16;
private static final int BOTTOM_M = BOTTOM * 16;
private static final int RIGHT_M = RIGHT * 16;
private EdgeEffect[] mEffect = new EdgeEffect[4];
private float[] mMatrix = new float[4 * 16];
public EdgeView(Context context) {
for (int i = 0; i < 4; i++) {
mEffect[i] = new EdgeEffect(context);
}
}
@Override
protected void onLayout(
boolean changeSize, int left, int top, int right, int bottom) {
if (!changeSize) return;
int w = right - left;
int h = bottom - top;
for (int i = 0; i < 4; i++) {
if ((i & 1) == 0) { // top or bottom
mEffect[i].setSize(w, h);
} else { // left or right
mEffect[i].setSize(h, w);
}
}
// Set up transforms for the four edges. Without transforms an
// EdgeEffect draws the TOP edge from (0, 0) to (w, Y * h) where Y
// is some factor < 1. For other edges we need to move, rotate, and
// flip the effects into proper places.
Matrix.setIdentityM(mMatrix, TOP_M);
Matrix.setIdentityM(mMatrix, LEFT_M);
Matrix.setIdentityM(mMatrix, BOTTOM_M);
Matrix.setIdentityM(mMatrix, RIGHT_M);
Matrix.rotateM(mMatrix, LEFT_M, 90, 0, 0, 1);
Matrix.scaleM(mMatrix, LEFT_M, 1, -1, 1);
Matrix.translateM(mMatrix, BOTTOM_M, 0, h, 0);
Matrix.scaleM(mMatrix, BOTTOM_M, 1, -1, 1);
Matrix.translateM(mMatrix, RIGHT_M, w, 0, 0);
Matrix.rotateM(mMatrix, RIGHT_M, 90, 0, 0, 1);
}
@Override
protected void render(GLCanvas canvas) {
super.render(canvas);
boolean more = false;
for (int i = 0; i < 4; i++) {
canvas.save(GLCanvas.SAVE_FLAG_MATRIX);
canvas.multiplyMatrix(mMatrix, i * 16);
more |= mEffect[i].draw(canvas);
canvas.restore();
}
if (more) {
invalidate();
}
}
// Called when the content is pulled away from the edge.
// offset is in pixels. direction is one of {TOP, LEFT, BOTTOM, RIGHT}.
public void onPull(int offset, int direction) {
int fullLength = ((direction & 1) == 0) ? getWidth() : getHeight();
mEffect[direction].onPull((float)offset / fullLength);
if (!mEffect[direction].isFinished()) {
invalidate();
}
}
// Call when the object is released after being pulled.
public void onRelease() {
boolean more = false;
for (int i = 0; i < 4; i++) {
mEffect[i].onRelease();
more |= !mEffect[i].isFinished();
}
if (more) {
invalidate();
}
}
// Call when the effect absorbs an impact at the given velocity.
// Used when a fling reaches the scroll boundary. velocity is in pixels
// per second. direction is one of {TOP, LEFT, BOTTOM, RIGHT}.
public void onAbsorb(int velocity, int direction) {
mEffect[direction].onAbsorb(velocity);
if (!mEffect[direction].isFinished()) {
invalidate();
}
}
}