1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.view.animation;
18
19import android.graphics.Matrix;
20
21/**
22 * Special case of TranslateAnimation that translates only vertically, picking up the
23 * horizontal values from whatever is set on the Transformation already. When used in
24 * conjunction with a TranslateXAnimation, allows independent animation of x and y
25 * position.
26 * @hide
27 */
28public class TranslateYAnimation extends TranslateAnimation {
29    float[] mTmpValues = new float[9];
30
31    /**
32     * Constructor. Passes in 0 for the x parameters of TranslateAnimation
33     */
34    public TranslateYAnimation(float fromYDelta, float toYDelta) {
35        super(0, 0, fromYDelta, toYDelta);
36    }
37
38    /**
39     * Constructor. Passes in 0 for the x parameters of TranslateAnimation
40     */
41    public TranslateYAnimation(int fromYType, float fromYValue, int toYType, float toYValue) {
42        super(ABSOLUTE, 0, ABSOLUTE, 0, fromYType, fromYValue, toYType, toYValue);
43    }
44
45    /**
46     * Calculates and sets y translation values on given transformation.
47     */
48    @Override
49    protected void applyTransformation(float interpolatedTime, Transformation t) {
50        Matrix m = t.getMatrix();
51        m.getValues(mTmpValues);
52        float dy = mFromYDelta + ((mToYDelta - mFromYDelta) * interpolatedTime);
53        t.getMatrix().setTranslate(mTmpValues[Matrix.MTRANS_X], dy);
54    }
55}
56