RotateAnimation.java revision 54b6cfa9a9e5b861a9930af873580d6dc20f773c 
1/*
2 * Copyright (C) 2006 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.content.Context;
20import android.content.res.TypedArray;
21import android.util.AttributeSet;
22
23/**
24 * An animation that controls the rotation of an object. This rotation takes
25 * place int the X-Y plane. You can specify the point to use for the center of
26 * the rotation, where (0,0) is the top left point. If not specified, (0,0) is
27 * the default rotation point.
28 *
29 */
30public class RotateAnimation extends Animation {
31    private float mFromDegrees;
32    private float mToDegrees;
33
34    private int mPivotXType = ABSOLUTE;
35    private int mPivotYType = ABSOLUTE;
36    private float mPivotXValue = 0.0f;
37    private float mPivotYValue = 0.0f;
38
39    private float mPivotX;
40    private float mPivotY;
41
42    /**
43     * Constructor used whan an RotateAnimation is loaded from a resource.
44     *
45     * @param context Application context to use
46     * @param attrs Attribute set from which to read values
47     */
48    public RotateAnimation(Context context, AttributeSet attrs) {
49        super(context, attrs);
50
51        TypedArray a = context.obtainStyledAttributes(attrs,
52                com.android.internal.R.styleable.RotateAnimation);
53
54        mFromDegrees = a.getFloat(
55                com.android.internal.R.styleable.RotateAnimation_fromDegrees, 0.0f);
56        mToDegrees = a.getFloat(com.android.internal.R.styleable.RotateAnimation_toDegrees, 0.0f);
57
58        Description d = Description.parseValue(a.peekValue(
59            com.android.internal.R.styleable.RotateAnimation_pivotX));
60        mPivotXType = d.type;
61        mPivotXValue = d.value;
62
63        d = Description.parseValue(a.peekValue(
64            com.android.internal.R.styleable.RotateAnimation_pivotY));
65        mPivotYType = d.type;
66        mPivotYValue = d.value;
67
68        a.recycle();
69    }
70
71    /**
72     * Constructor to use when building a RotateAnimation from code.
73     * Default pivotX/pivotY point is (0,0).
74     *
75     * @param fromDegrees Rotation offset to apply at the start of the
76     *        animation.
77     *
78     * @param toDegrees Rotation offset to apply at the end of the animation.
79     */
80    public RotateAnimation(float fromDegrees, float toDegrees) {
81        mFromDegrees = fromDegrees;
82        mToDegrees = toDegrees;
83        mPivotX = 0.0f;
84        mPivotY = 0.0f;
85    }
86
87    /**
88     * Constructor to use when building a RotateAnimation from code
89     *
90     * @param fromDegrees Rotation offset to apply at the start of the
91     *        animation.
92     *
93     * @param toDegrees Rotation offset to apply at the end of the animation.
94     *
95     * @param pivotX The X coordinate of the point about which the object is
96     *        being rotated, specified as an absolute number where 0 is the left
97     *        edge.
98     * @param pivotY The Y coordinate of the point about which the object is
99     *        being rotated, specified as an absolute number where 0 is the top
100     *        edge.
101     */
102    public RotateAnimation(float fromDegrees, float toDegrees, float pivotX, float pivotY) {
103        mFromDegrees = fromDegrees;
104        mToDegrees = toDegrees;
105
106        mPivotXType = ABSOLUTE;
107        mPivotYType = ABSOLUTE;
108        mPivotXValue = pivotX;
109        mPivotYValue = pivotY;
110    }
111
112    /**
113     * Constructor to use when building a RotateAnimation from code
114     *
115     * @param fromDegrees Rotation offset to apply at the start of the
116     *        animation.
117     *
118     * @param toDegrees Rotation offset to apply at the end of the animation.
119     *
120     * @param pivotXType Specifies how pivotXValue should be interpreted. One of
121     *        Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or
122     *        Animation.RELATIVE_TO_PARENT.
123     * @param pivotXValue The X coordinate of the point about which the object
124     *        is being rotated, specified as an absolute number where 0 is the
125     *        left edge. This value can either be an absolute number if
126     *        pivotXType is ABSOLUTE, or a percentage (where 1.0 is 100%)
127     *        otherwise.
128     * @param pivotYType Specifies how pivotYValue should be interpreted. One of
129     *        Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or
130     *        Animation.RELATIVE_TO_PARENT.
131     * @param pivotYValue The Y coordinate of the point about which the object
132     *        is being rotated, specified as an absolute number where 0 is the
133     *        top edge. This value can either be an absolute number if
134     *        pivotYType is ABSOLUTE, or a percentage (where 1.0 is 100%)
135     *        otherwise.
136     */
137    public RotateAnimation(float fromDegrees, float toDegrees, int pivotXType, float pivotXValue,
138            int pivotYType, float pivotYValue) {
139        mFromDegrees = fromDegrees;
140        mToDegrees = toDegrees;
141
142        mPivotXValue = pivotXValue;
143        mPivotXType = pivotXType;
144        mPivotYValue = pivotYValue;
145        mPivotYType = pivotYType;
146    }
147
148    @Override
149    protected void applyTransformation(float interpolatedTime, Transformation t) {
150        float degrees = mFromDegrees + ((mToDegrees - mFromDegrees) * interpolatedTime);
151
152        if (mPivotX == 0.0f && mPivotY == 0.0f) {
153            t.getMatrix().setRotate(degrees);
154        } else {
155            t.getMatrix().setRotate(degrees, mPivotX, mPivotY);
156        }
157    }
158
159    @Override
160    public void initialize(int width, int height, int parentWidth, int parentHeight) {
161        super.initialize(width, height, parentWidth, parentHeight);
162        mPivotX = resolveSize(mPivotXType, mPivotXValue, width, parentWidth);
163        mPivotY = resolveSize(mPivotYType, mPivotYValue, height, parentHeight);
164    }
165}
166