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39 | |
40 | #include "qquickbehavior_p.h" |
41 | |
42 | #include "qquickanimation_p.h" |
43 | #include <qqmlcontext.h> |
44 | #include <qqmlinfo.h> |
45 | #include <private/qqmlproperty_p.h> |
46 | #include <private/qqmlengine_p.h> |
47 | #include <private/qabstractanimationjob_p.h> |
48 | #include <private/qquicktransition_p.h> |
49 | |
50 | #include <private/qquickanimatorjob_p.h> |
51 | |
52 | #include <private/qobject_p.h> |
53 | |
54 | QT_BEGIN_NAMESPACE |
55 | |
56 | class QQuickBehaviorPrivate : public QObjectPrivate, public QAnimationJobChangeListener |
57 | { |
58 | Q_DECLARE_PUBLIC(QQuickBehavior) |
59 | public: |
60 | QQuickBehaviorPrivate() : animation(nullptr), animationInstance(nullptr), enabled(true), finalized(false) |
61 | , blockRunningChanged(false) {} |
62 | |
63 | void animationStateChanged(QAbstractAnimationJob *, QAbstractAnimationJob::State newState, QAbstractAnimationJob::State oldState) override; |
64 | |
65 | QQmlProperty property; |
66 | QVariant targetValue; |
67 | QPointer<QQuickAbstractAnimation> animation; |
68 | QAbstractAnimationJob *animationInstance; |
69 | bool enabled; |
70 | bool finalized; |
71 | bool blockRunningChanged; |
72 | }; |
73 | |
74 | /*! |
75 | \qmltype Behavior |
76 | \instantiates QQuickBehavior |
77 | \inqmlmodule QtQuick |
78 | \ingroup qtquick-transitions-animations |
79 | \ingroup qtquick-interceptors |
80 | \brief Defines a default animation for a property change. |
81 | |
82 | A Behavior defines the default animation to be applied whenever a |
83 | particular property value changes. |
84 | |
85 | For example, the following Behavior defines a NumberAnimation to be run |
86 | whenever the \l Rectangle's \c width value changes. When the MouseArea |
87 | is clicked, the \c width is changed, triggering the behavior's animation: |
88 | |
89 | \snippet qml/behavior.qml 0 |
90 | |
91 | Note that a property cannot have more than one assigned Behavior. To provide |
92 | multiple animations within a Behavior, use ParallelAnimation or |
93 | SequentialAnimation. |
94 | |
95 | If a \l{Qt Quick States}{state change} has a \l Transition that matches the same property as a |
96 | Behavior, the \l Transition animation overrides the Behavior for that |
97 | state change. For general advice on using Behaviors to animate state changes, see |
98 | \l{Using Qt Quick Behaviors with States}. |
99 | |
100 | \sa {Animation and Transitions in Qt Quick}, {Qt Quick Examples - Animation#Behaviors}{Behavior example}, {Qt QML} |
101 | */ |
102 | |
103 | |
104 | QQuickBehavior::QQuickBehavior(QObject *parent) |
105 | : QObject(*(new QQuickBehaviorPrivate), parent) |
106 | { |
107 | } |
108 | |
109 | QQuickBehavior::~QQuickBehavior() |
110 | { |
111 | Q_D(QQuickBehavior); |
112 | delete d->animationInstance; |
113 | } |
114 | |
115 | /*! |
116 | \qmlproperty Animation QtQuick::Behavior::animation |
117 | \default |
118 | |
119 | This property holds the animation to run when the behavior is triggered. |
120 | */ |
121 | |
122 | QQuickAbstractAnimation *QQuickBehavior::animation() |
123 | { |
124 | Q_D(QQuickBehavior); |
125 | return d->animation; |
126 | } |
127 | |
128 | void QQuickBehavior::setAnimation(QQuickAbstractAnimation *animation) |
129 | { |
130 | Q_D(QQuickBehavior); |
131 | if (d->animation) { |
132 | qmlWarning(me: this) << tr(s: "Cannot change the animation assigned to a Behavior." ); |
133 | return; |
134 | } |
135 | |
136 | d->animation = animation; |
137 | if (d->animation) { |
138 | d->animation->setDefaultTarget(d->property); |
139 | d->animation->setDisableUserControl(); |
140 | } |
141 | } |
142 | |
143 | |
144 | void QQuickBehaviorPrivate::animationStateChanged(QAbstractAnimationJob *, QAbstractAnimationJob::State newState,QAbstractAnimationJob::State) |
145 | { |
146 | if (!blockRunningChanged && animation) |
147 | animation->notifyRunningChanged(running: newState == QAbstractAnimationJob::Running); |
148 | } |
149 | |
150 | /*! |
151 | \qmlproperty bool QtQuick::Behavior::enabled |
152 | |
153 | This property holds whether the behavior will be triggered when the tracked |
154 | property changes value. |
155 | |
156 | By default a Behavior is enabled. |
157 | */ |
158 | |
159 | bool QQuickBehavior::enabled() const |
160 | { |
161 | Q_D(const QQuickBehavior); |
162 | return d->enabled; |
163 | } |
164 | |
165 | void QQuickBehavior::setEnabled(bool enabled) |
166 | { |
167 | Q_D(QQuickBehavior); |
168 | if (d->enabled == enabled) |
169 | return; |
170 | d->enabled = enabled; |
171 | emit enabledChanged(); |
172 | } |
173 | |
174 | /*! |
175 | \qmlproperty Variant QtQuick::Behavior::targetValue |
176 | |
177 | This property holds the target value of the property being controlled by the Behavior. |
178 | This value is set by the Behavior before the animation is started. |
179 | |
180 | \since QtQuick 2.13 |
181 | */ |
182 | QVariant QQuickBehavior::targetValue() const |
183 | { |
184 | Q_D(const QQuickBehavior); |
185 | return d->targetValue; |
186 | } |
187 | |
188 | /*! |
189 | \readonly |
190 | \qmlpropertygroup QtQuick::Behavior::targetProperty |
191 | \qmlproperty string QtQuick::Behavior::targetProperty.name |
192 | \qmlproperty Object QtQuick::Behavior::targetProperty.object |
193 | |
194 | \table |
195 | \header |
196 | \li Property |
197 | \li Description |
198 | \row |
199 | \li name |
200 | \li This property holds the name of the property being controlled by this Behavior. |
201 | \row |
202 | \li object |
203 | \li This property holds the object of the property being controlled by this Behavior. |
204 | \endtable |
205 | |
206 | This property can be used to define custom behaviors based on the name or the object of |
207 | the property being controlled. |
208 | |
209 | The following example defines a Behavior fading out and fading in its target object |
210 | when the property it controls changes: |
211 | \qml |
212 | // FadeBehavior.qml |
213 | import QtQuick 2.15 |
214 | |
215 | Behavior { |
216 | id: root |
217 | property Item fadeTarget: targetProperty.object |
218 | SequentialAnimation { |
219 | NumberAnimation { |
220 | target: root.fadeTarget |
221 | property: "opacity" |
222 | to: 0 |
223 | easing.type: Easing.InQuad |
224 | } |
225 | PropertyAction { } // actually change the controlled property between the 2 other animations |
226 | NumberAnimation { |
227 | target: root.fadeTarget |
228 | property: "opacity" |
229 | to: 1 |
230 | easing.type: Easing.OutQuad |
231 | } |
232 | } |
233 | } |
234 | \endqml |
235 | |
236 | This can be used to animate a text when it changes: |
237 | \qml |
238 | import QtQuick 2.15 |
239 | |
240 | Text { |
241 | id: root |
242 | property int counter |
243 | text: counter |
244 | FadeBehavior on text {} |
245 | Timer { |
246 | running: true |
247 | repeat: true |
248 | interval: 1000 |
249 | onTriggered: ++root.counter |
250 | } |
251 | } |
252 | \endqml |
253 | |
254 | \since QtQuick 2.15 |
255 | */ |
256 | QQmlProperty QQuickBehavior::targetProperty() const |
257 | { |
258 | Q_D(const QQuickBehavior); |
259 | return d->property; |
260 | } |
261 | |
262 | void QQuickBehavior::write(const QVariant &value) |
263 | { |
264 | Q_D(QQuickBehavior); |
265 | const bool targetValueHasChanged = d->targetValue != value; |
266 | if (targetValueHasChanged) { |
267 | d->targetValue = value; |
268 | emit targetValueChanged(); // emitting the signal here should allow |
269 | } // d->enabled to change if scripted by the user. |
270 | bool bypass = !d->enabled || !d->finalized || QQmlEnginePrivate::designerMode(); |
271 | if (!bypass) |
272 | qmlExecuteDeferred(this); |
273 | if (QQmlData::wasDeleted(object: d->animation) || bypass) { |
274 | if (d->animationInstance) |
275 | d->animationInstance->stop(); |
276 | QQmlPropertyPrivate::write(that: d->property, value, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding); |
277 | return; |
278 | } |
279 | |
280 | bool behaviorActive = d->animation->isRunning(); |
281 | if (behaviorActive && !targetValueHasChanged) |
282 | return; |
283 | |
284 | if (d->animationInstance |
285 | && (d->animationInstance->duration() != -1 |
286 | || d->animationInstance->isRenderThreadProxy()) |
287 | && !d->animationInstance->isStopped()) { |
288 | d->blockRunningChanged = true; |
289 | d->animationInstance->stop(); |
290 | } |
291 | // Render thread animations use "stop" to synchronize the property back |
292 | // to the item, so we need to read the value after. |
293 | const QVariant ¤tValue = d->property.read(); |
294 | |
295 | // Don't unnecessarily wake up the animation system if no real animation |
296 | // is needed (value has not changed). If the Behavior was already |
297 | // running, let it continue as normal to ensure correct behavior and state. |
298 | if (!behaviorActive && d->targetValue == currentValue) { |
299 | QQmlPropertyPrivate::write(that: d->property, value, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding); |
300 | return; |
301 | } |
302 | |
303 | QQuickStateOperation::ActionList actions; |
304 | QQuickStateAction action; |
305 | action.property = d->property; |
306 | action.fromValue = currentValue; |
307 | action.toValue = value; |
308 | actions << action; |
309 | |
310 | QList<QQmlProperty> after; |
311 | QAbstractAnimationJob *prev = d->animationInstance; |
312 | d->animationInstance = d->animation->transition(actions, modified&: after, direction: QQuickAbstractAnimation::Forward); |
313 | |
314 | if (d->animationInstance && d->animation->threadingModel() == QQuickAbstractAnimation::RenderThread) |
315 | d->animationInstance = new QQuickAnimatorProxyJob(d->animationInstance, d->animation); |
316 | |
317 | if (prev && prev != d->animationInstance) |
318 | delete prev; |
319 | |
320 | if (d->animationInstance) { |
321 | if (d->animationInstance != prev) |
322 | d->animationInstance->addAnimationChangeListener(listener: d, QAbstractAnimationJob::StateChange); |
323 | d->animationInstance->start(); |
324 | d->blockRunningChanged = false; |
325 | } |
326 | if (!after.contains(t: d->property)) |
327 | QQmlPropertyPrivate::write(that: d->property, value, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding); |
328 | } |
329 | |
330 | void QQuickBehavior::setTarget(const QQmlProperty &property) |
331 | { |
332 | Q_D(QQuickBehavior); |
333 | d->property = property; |
334 | if (d->animation) |
335 | d->animation->setDefaultTarget(property); |
336 | |
337 | QQmlEnginePrivate *engPriv = QQmlEnginePrivate::get(e: qmlEngine(this)); |
338 | static int finalizedIdx = -1; |
339 | if (finalizedIdx < 0) |
340 | finalizedIdx = metaObject()->indexOfSlot(slot: "componentFinalized()" ); |
341 | engPriv->registerFinalizeCallback(obj: this, index: finalizedIdx); |
342 | |
343 | Q_EMIT targetPropertyChanged(); |
344 | } |
345 | |
346 | void QQuickBehavior::componentFinalized() |
347 | { |
348 | Q_D(QQuickBehavior); |
349 | d->finalized = true; |
350 | } |
351 | |
352 | QT_END_NAMESPACE |
353 | |
354 | #include "moc_qquickbehavior_p.cpp" |
355 | |