1/*
2 * Copyright (C) 2013 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.transition;
18
19import android.animation.Animator;
20import android.animation.AnimatorListenerAdapter;
21import android.animation.AnimatorSet;
22import android.animation.ValueAnimator;
23import android.graphics.Color;
24import android.util.Log;
25import android.view.ViewGroup;
26import android.widget.EditText;
27import android.widget.TextView;
28
29import java.util.Map;
30
31/**
32 * This transition tracks changes to the text in TextView targets. If the text
33 * changes between the start and end scenes, the transition ensures that the
34 * starting text stays until the transition ends, at which point it changes
35 * to the end text.  This is useful in situations where you want to resize a
36 * text view to its new size before displaying the text that goes there.
37 *
38 * @hide
39 */
40public class ChangeText extends Transition {
41
42    private static final String LOG_TAG = "TextChange";
43
44    private static final String PROPNAME_TEXT = "android:textchange:text";
45    private static final String PROPNAME_TEXT_SELECTION_START =
46            "android:textchange:textSelectionStart";
47    private static final String PROPNAME_TEXT_SELECTION_END =
48            "android:textchange:textSelectionEnd";
49    private static final String PROPNAME_TEXT_COLOR = "android:textchange:textColor";
50
51    private int mChangeBehavior = CHANGE_BEHAVIOR_KEEP;
52
53    /**
54     * Flag specifying that the text in affected/changing TextView targets will keep
55     * their original text during the transition, setting it to the final text when
56     * the transition ends. This is the default behavior.
57     *
58     * @see #setChangeBehavior(int)
59     */
60    public static final int CHANGE_BEHAVIOR_KEEP = 0;
61    /**
62     * Flag specifying that the text changing animation should first fade
63     * out the original text completely. The new text is set on the target
64     * view at the end of the fade-out animation. This transition is typically
65     * used with a later {@link #CHANGE_BEHAVIOR_IN} transition, allowing more
66     * flexibility than the {@link #CHANGE_BEHAVIOR_OUT_IN} by allowing other
67     * transitions to be run sequentially or in parallel with these fades.
68     *
69     * @see #setChangeBehavior(int)
70     */
71    public static final int CHANGE_BEHAVIOR_OUT = 1;
72    /**
73     * Flag specifying that the text changing animation should fade in the
74     * end text into the affected target view(s). This transition is typically
75     * used in conjunction with an earlier {@link #CHANGE_BEHAVIOR_OUT}
76     * transition, possibly with other transitions running as well, such as
77     * a sequence to fade out, then resize the view, then fade in.
78     *
79     * @see #setChangeBehavior(int)
80     */
81    public static final int CHANGE_BEHAVIOR_IN = 2;
82    /**
83     * Flag specifying that the text changing animation should first fade
84     * out the original text completely and then fade in the
85     * new text.
86     *
87     * @see #setChangeBehavior(int)
88     */
89    public static final int CHANGE_BEHAVIOR_OUT_IN = 3;
90
91    private static final String[] sTransitionProperties = {
92            PROPNAME_TEXT,
93            PROPNAME_TEXT_SELECTION_START,
94            PROPNAME_TEXT_SELECTION_END
95    };
96
97    /**
98     * Sets the type of changing animation that will be run, one of
99     * {@link #CHANGE_BEHAVIOR_KEEP}, {@link #CHANGE_BEHAVIOR_OUT},
100     * {@link #CHANGE_BEHAVIOR_IN}, and {@link #CHANGE_BEHAVIOR_OUT_IN}.
101     *
102     * @param changeBehavior The type of fading animation to use when this
103     * transition is run.
104     * @return this textChange object.
105     */
106    public ChangeText setChangeBehavior(int changeBehavior) {
107        if (changeBehavior >= CHANGE_BEHAVIOR_KEEP && changeBehavior <= CHANGE_BEHAVIOR_OUT_IN) {
108            mChangeBehavior = changeBehavior;
109        }
110        return this;
111    }
112
113    @Override
114    public String[] getTransitionProperties() {
115        return sTransitionProperties;
116    }
117
118    /**
119     * Returns the type of changing animation that will be run.
120     *
121     * @return either {@link #CHANGE_BEHAVIOR_KEEP}, {@link #CHANGE_BEHAVIOR_OUT},
122     * {@link #CHANGE_BEHAVIOR_IN}, or {@link #CHANGE_BEHAVIOR_OUT_IN}.
123     */
124    public int getChangeBehavior() {
125        return mChangeBehavior;
126    }
127
128    private void captureValues(TransitionValues transitionValues) {
129        if (transitionValues.view instanceof TextView) {
130            TextView textview = (TextView) transitionValues.view;
131            transitionValues.values.put(PROPNAME_TEXT, textview.getText());
132            if (textview instanceof EditText) {
133                transitionValues.values.put(PROPNAME_TEXT_SELECTION_START,
134                        textview.getSelectionStart());
135                transitionValues.values.put(PROPNAME_TEXT_SELECTION_END,
136                        textview.getSelectionEnd());
137            }
138            if (mChangeBehavior > CHANGE_BEHAVIOR_KEEP) {
139                transitionValues.values.put(PROPNAME_TEXT_COLOR, textview.getCurrentTextColor());
140            }
141        }
142    }
143
144    @Override
145    public void captureStartValues(TransitionValues transitionValues) {
146        captureValues(transitionValues);
147    }
148
149    @Override
150    public void captureEndValues(TransitionValues transitionValues) {
151        captureValues(transitionValues);
152    }
153
154    @Override
155    public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues,
156            TransitionValues endValues) {
157        if (startValues == null || endValues == null ||
158                !(startValues.view instanceof TextView) || !(endValues.view instanceof TextView)) {
159            return null;
160        }
161        final TextView view = (TextView) endValues.view;
162        Map<String, Object> startVals = startValues.values;
163        Map<String, Object> endVals = endValues.values;
164        final CharSequence startText = startVals.get(PROPNAME_TEXT) != null ?
165                (CharSequence) startVals.get(PROPNAME_TEXT) : "";
166        final CharSequence endText = endVals.get(PROPNAME_TEXT) != null ?
167                (CharSequence) endVals.get(PROPNAME_TEXT) : "";
168        final int startSelectionStart, startSelectionEnd, endSelectionStart, endSelectionEnd;
169        if (view instanceof EditText) {
170            startSelectionStart = startVals.get(PROPNAME_TEXT_SELECTION_START) != null ?
171                    (Integer) startVals.get(PROPNAME_TEXT_SELECTION_START) : -1;
172            startSelectionEnd = startVals.get(PROPNAME_TEXT_SELECTION_END) != null ?
173                    (Integer) startVals.get(PROPNAME_TEXT_SELECTION_END) : startSelectionStart;
174            endSelectionStart = endVals.get(PROPNAME_TEXT_SELECTION_START) != null ?
175                    (Integer) endVals.get(PROPNAME_TEXT_SELECTION_START) : -1;
176            endSelectionEnd = endVals.get(PROPNAME_TEXT_SELECTION_END) != null ?
177                    (Integer) endVals.get(PROPNAME_TEXT_SELECTION_END) : endSelectionStart;
178        } else {
179            startSelectionStart = startSelectionEnd = endSelectionStart = endSelectionEnd = -1;
180        }
181        if (!startText.equals(endText)) {
182            final int startColor;
183            final int endColor;
184            if (mChangeBehavior != CHANGE_BEHAVIOR_IN) {
185                view.setText(startText);
186                if (view instanceof EditText) {
187                    setSelection(((EditText) view), startSelectionStart, startSelectionEnd);
188                }
189            }
190            Animator anim;
191            if (mChangeBehavior == CHANGE_BEHAVIOR_KEEP) {
192                startColor = endColor = 0;
193                anim = ValueAnimator.ofFloat(0, 1);
194                anim.addListener(new AnimatorListenerAdapter() {
195                    @Override
196                    public void onAnimationEnd(Animator animation) {
197                        if (startText.equals(view.getText())) {
198                            // Only set if it hasn't been changed since anim started
199                            view.setText(endText);
200                            if (view instanceof EditText) {
201                                setSelection(((EditText) view), endSelectionStart, endSelectionEnd);
202                            }
203                        }
204                    }
205                });
206            } else {
207                startColor = (Integer) startVals.get(PROPNAME_TEXT_COLOR);
208                endColor = (Integer) endVals.get(PROPNAME_TEXT_COLOR);
209                // Fade out start text
210                ValueAnimator outAnim = null, inAnim = null;
211                if (mChangeBehavior == CHANGE_BEHAVIOR_OUT_IN ||
212                        mChangeBehavior == CHANGE_BEHAVIOR_OUT) {
213                    outAnim = ValueAnimator.ofInt(255, 0);
214                    outAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
215                        @Override
216                        public void onAnimationUpdate(ValueAnimator animation) {
217                            int currAlpha = (Integer) animation.getAnimatedValue();
218                            view.setTextColor(currAlpha << 24 | startColor & 0xff0000 |
219                                    startColor & 0xff00 | startColor & 0xff);
220                        }
221                    });
222                    outAnim.addListener(new AnimatorListenerAdapter() {
223                        @Override
224                        public void onAnimationEnd(Animator animation) {
225                            if (startText.equals(view.getText())) {
226                                // Only set if it hasn't been changed since anim started
227                                view.setText(endText);
228                                if (view instanceof EditText) {
229                                    setSelection(((EditText) view), endSelectionStart,
230                                            endSelectionEnd);
231                                }
232                            }
233                            // restore opaque alpha and correct end color
234                            view.setTextColor(endColor);
235                        }
236                    });
237                }
238                if (mChangeBehavior == CHANGE_BEHAVIOR_OUT_IN ||
239                        mChangeBehavior == CHANGE_BEHAVIOR_IN) {
240                    inAnim = ValueAnimator.ofInt(0, 255);
241                    inAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
242                        @Override
243                        public void onAnimationUpdate(ValueAnimator animation) {
244                            int currAlpha = (Integer) animation.getAnimatedValue();
245                            view.setTextColor(currAlpha << 24 | Color.red(endColor) << 16 |
246                                    Color.green(endColor) << 8 | Color.red(endColor));
247                        }
248                    });
249                    inAnim.addListener(new AnimatorListenerAdapter() {
250                        @Override
251                        public void onAnimationCancel(Animator animation) {
252                            // restore opaque alpha and correct end color
253                            view.setTextColor(endColor);
254                        }
255                    });
256                }
257                if (outAnim != null && inAnim != null) {
258                    anim = new AnimatorSet();
259                    ((AnimatorSet) anim).playSequentially(outAnim, inAnim);
260                } else if (outAnim != null) {
261                    anim = outAnim;
262                } else {
263                    // Must be an in-only animation
264                    anim = inAnim;
265                }
266            }
267            TransitionListener transitionListener = new TransitionListenerAdapter() {
268                int mPausedColor = 0;
269
270                @Override
271                public void onTransitionPause(Transition transition) {
272                    if (mChangeBehavior != CHANGE_BEHAVIOR_IN) {
273                        view.setText(endText);
274                        if (view instanceof EditText) {
275                            setSelection(((EditText) view), endSelectionStart, endSelectionEnd);
276                        }
277                    }
278                    if (mChangeBehavior > CHANGE_BEHAVIOR_KEEP) {
279                        mPausedColor = view.getCurrentTextColor();
280                        view.setTextColor(endColor);
281                    }
282                }
283
284                @Override
285                public void onTransitionResume(Transition transition) {
286                    if (mChangeBehavior != CHANGE_BEHAVIOR_IN) {
287                        view.setText(startText);
288                        if (view instanceof EditText) {
289                            setSelection(((EditText) view), startSelectionStart, startSelectionEnd);
290                        }
291                    }
292                    if (mChangeBehavior > CHANGE_BEHAVIOR_KEEP) {
293                        view.setTextColor(mPausedColor);
294                    }
295                }
296            };
297            addListener(transitionListener);
298            if (DBG) {
299                Log.d(LOG_TAG, "createAnimator returning " + anim);
300            }
301            return anim;
302        }
303        return null;
304    }
305
306    private void setSelection(EditText editText, int start, int end) {
307        if (start >= 0 && end >= 0) {
308            editText.setSelection(start, end);
309        }
310    }
311}
312