qstmgesturelib/qstmgestureengine_if.h
changeset 0 1450b09d0cfd
child 16 3c88a81ff781
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/qstmgesturelib/qstmgestureengine_if.h	Tue May 04 12:39:35 2010 +0300
@@ -0,0 +1,277 @@
+/*
+* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU Lesser General Public License as published by
+* the Free Software Foundation, version 2.1 of the License.
+* 
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this program.  If not, 
+* see "http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html/".
+*
+* Description:
+*
+*/
+#ifndef QSTMGESTURELISTENER_IF_H_
+#define QSTMGESTURELISTENER_IF_H_
+
+
+#include "qstmgesturelistener_if.h"
+#include "qstmgesture_if.h"
+
+namespace qstmUiEventEngine
+{
+    class QStm_UiEventIf ;
+}
+
+namespace qstmGesture
+{
+
+// Forward declarations
+class QStm_GestureRecogniserIf ;
+
+/*!
+ *  QStm_GestureRecogniserIf defines the methods for the gesture recognisers
+ *  to be added to the gesture engine.
+ *  TODO: add rule based settings to position the gesture recognisers to the list.
+ *  The gesture recogniser order rules would be defined how?
+ *  - defining the order inside the application
+ *  - defining the order in some configuration file (maybe not)
+ *
+ *  This requires:
+ *  - the gesture recognisers need to have an ID
+ *  - a type can also be defined if the rules can be set based on types.
+ *
+ *  The gesture recognisers are arranged in a list so that the correct gesture recogniser
+ *  gets the opportunity to detect the gesture in time.  An axample of a set of gesture recognisers
+ *  could be e.g.
+ *
+ *  |---------------------------------------------|
+ *  |  scrolling stop by tap -gesture recogniser  | A is enabled only when needed, when enabled must precede all others
+ *  |                                             |   (note that locking partly can be used to achieve the same)
+ *  |---------------------------------------------|
+ *  | location specific: zoom + button tap gesture| B these must detect the location first
+ *  |---------------------------------------------|
+ *  | location specific: zoom - button tap gesture| B these must detect the location first
+ *  |---------------------------------------------|
+ *  | location specific: edge scroll gesture      | B these must detect the location first
+ *  |---------------------------------------------|
+ *  | pinch zoom gesture                          |   standard gesture, but application wide (spans windows)
+ *  |                                             | C another requirement: disable all but me/restore state
+ *  |                                             |   so that other gestures will not meddle in while pinching
+ *  |---------------------------------------------|
+ *  | hover gesture                               | C standard gesture, needs to detect the EMove speed
+ *  |---------------------------------------------|
+ *  | pan gesture                                 | C standard gesture, but must be after hover
+ *  |---------------------------------------------|
+ *  | tap/doubletap gesture                       | C standard gesture, order not that important, since
+ *  |                                             |   needs just to see certain events in history: touch/release
+ *  |---------------------------------------------|
+ *
+ *  The order of gesture recognisers determine how the system behaves, so there must be an easy way
+ *  to define the order.  The order could be defined either by specifying the IDs or just their types, if then the
+ *  order is not that important.  TODO to study whether it would be a good idea to implement this so that
+ *  there are separate lists for the three different classes of gesture recognisers A, B and C; this might
+ *  make the implementation simpler.
+ */
+class QStm_GestureEngineIf
+{
+public:
+	QStm_GestureEngineIf() {}
+    /*!
+     *  add gesture to the end of the list of gestures
+     */
+    virtual bool addGesture(const QStm_GestureRecogniserIf* newGesture) = 0 ;
+    /*!
+     * inset a gesture to specific position
+     */
+    virtual bool insertGesture(const QStm_GestureRecogniserIf* newGesture, int position) = 0 ;
+
+    virtual int findGesture(const QStm_GestureRecogniserIf* newGesture, int startPos = 0) const = 0;
+    virtual int findGestureReverse(const QStm_GestureRecogniserIf* gesture, int astartPos) const = 0;
+    virtual int findGesture(QStm_GestureUid uid, int startPos = 0) const = 0;
+    virtual int findGestureReverse(QStm_GestureUid uid, int startPos) const = 0;
+    virtual int gestureCount() const = 0;
+    virtual QStm_GestureRecogniserIf* gestureAt(int idx) = 0;
+
+    /*!
+     * remove a gesture from the list
+     */
+    virtual bool removeGesture(const QStm_GestureRecogniserIf* oldGesture) = 0 ;
+    /*!
+     * get the number of non-empty event streams.
+     * Event streams correspond UI events generated by one touch pointer (=finger).
+     * The low level state machine handles the necessary filtering etc.
+     * so that it is safe to remove the event stream after UI Release event has been processed.
+     */
+    virtual int activeStreamCount() const = 0 ;
+    /*!
+     * get the UI events of stream X
+     * \param indexOfActiveStream defines which active stream is used.
+     * Note that QStm_UiEventIf contains all the events from down up to the current event.
+     * Assumption: the UI events contain the target "window handle", i.e.
+     * the gesture recognition needs to be aware of all possible windows of the application.
+     */
+    virtual const qstmUiEventEngine::QStm_UiEventIf* getUiEvents(int indexOfActiveStream) const = 0 ;
+    /*!
+     * Enable/disable logging
+     */
+    virtual void enableLogging(bool aLoggingEnabled) = 0 ;
+};
+
+/*!
+ * Enumerated values for the gesture recogniser
+ */
+enum QStm_GestureRecognitionState
+{
+    EGestureActive,     /*! < gesture recognised and gesture notification sent */
+    ELockToThisGesture, /*! < gesture recognised, and only this recogniser called until release/this returns something else */
+    ENotMyGesture       /*! < not this gesture, try the next one in the list  */
+};
+
+/*!
+ * The types of gesture recognisers. TODO to implement rule based gesture engine
+ * where the recognisers can be added in any order, and the rules define the order of them.
+ * The rules may define
+ */
+enum QStm_GestureRecogniserType
+{
+    ECriticalGestureRecogniser,           /*! < This kind of gestures should be at the beginning of the list */
+    ELocationSpecificGestureRecogniser,   /*! < This kind of gestures should be at the next in the list */
+    EGenericGestureRecogniser             /*! < This kind of gestures should be at the next in the list */
+};
+
+/*!
+ * QStm_GestureRecogniserIf defines the interface needed to be implemented by every gesture recognition element.
+ * The gesture recogniser gets the UI events and needs to determine whether they define the expected gesture.
+ *
+ */
+class QStm_GestureRecogniserIf
+{
+public:
+	QStm_GestureRecogniserIf() {}
+    /*!
+     *  Virtual destuructor.
+     */
+    virtual ~QStm_GestureRecogniserIf() {}
+    /*!
+     * Process the UI event.
+     * \param numOfActiveStreams : indicates how many pointers are currently active.
+     * \param ge the gesture engine.  The Gesture recogniser uses this to get the current active events.
+     *
+     * \return EMaybeGesture    if gesture was not yet recognised but can be possible (e.g. after first touch everyone returns this)
+     * \return EGestureActive   if gesture was recognised and a gesture notification was sent; this is then the active gesture
+     * \return ENotMygesture    if gesture can not be this one, e.g. TAP gesture after receiving Move UI event.
+     *
+     * Note that a gesture may take control only if it sends out a gesture notification. (or is it so?)
+     * Until no gesture recogniser has sent a gesture notification, all recognisers who have not returned
+     * ENotMyGesture are eligible, based on the order they are in the list.
+     *
+     * The gesture engine may be either in dynamic gestures mode or fixed gestures mode.
+     * In dynamic gestures mode each time an UI event is processed, engine will call each
+     * gesture recogniser until one of the recognisers returns EGestureActive.
+     *
+     * In fixed gestures mode the index of the gesture recogniser first returning EGestureActive is stored
+     * and the subsequent UI events are processed so that only that recogniser is allowed to send gesture
+     * notification.  If it returns !=EGestureActive, it relinguishes the control.
+     *
+     */
+    virtual QStm_GestureRecognitionState recognise(int numOfActiveStreams, QStm_GestureEngineIf* ge) = 0 ;
+    /*!
+     * In dynamic gestures mode the gesture engine will call release of the recogniser
+     * who lost activation status because a preceding recogniser in the list took control.
+     *
+     * Note that the recogniser must then do whatever (if anything) is needed to cancel the gesture.
+     */
+    virtual void release(QStm_GestureEngineIf* ge) = 0  ;
+    /*!
+     * Enable or disable recogniser.  E.g. if two gestures are related so that
+     * a gesture ending recogniser needs to be activated to stop a t5imer driven
+     * behaviour it is useful to add the recogniser to the top of the list
+     * and then disable it until needed.
+     */
+    virtual void enable(bool enableRecogniser) = 0 ;
+    /*!
+     * Get the state of the gesture recogniser, whether it is enabled or not
+     * \return true, if the recogniser is enabled.
+     */
+    virtual bool isEnabled() = 0 ;
+    /*!
+     * Return the type of the gesture recogniser
+     */
+    virtual QStm_GestureUid gestureUid() const = 0;
+
+    /*!
+     * for testing purposes
+     */
+    virtual void enableLogging(bool loggingEnabled) = 0 ;
+
+    virtual void setOwner(void* owner) = 0;
+    
+    virtual QStm_GestureRecognitionState state() = 0;
+};
+
+class QStm_GestureRecogniser : public QObject, public QStm_GestureRecogniserIf
+{
+public:
+    virtual ~QStm_GestureRecogniser()
+    {
+
+    }
+    /*!
+     * MGestureRecogniserIf methods; partial implementation
+     */
+    virtual void enable(bool enabled)
+    {
+        m_gestureEnabled = enabled ;
+    }
+    
+    virtual bool isEnabled()
+    {
+        return m_gestureEnabled ;
+    }
+    
+    virtual void enableLogging(bool loggingOn)
+    {
+        m_loggingenabled = loggingOn;
+    }
+    
+    virtual void setOwner(void* owner)
+    {
+        m_powner = owner;
+    }
+    
+    virtual QStm_GestureRecognitionState state()
+    {
+        return m_state;
+    }
+    
+protected:
+    QStm_GestureRecogniser(QStm_GestureListenerIf* listener) : QStm_GestureRecogniserIf(),
+                           m_powner(listener->getOwner()), 
+                           m_listener(listener), 
+                           m_gestureEnabled(false), 
+                           m_loggingenabled(false),
+                           m_state(ENotMyGesture)
+    {
+
+    }
+
+protected:
+    void*                    m_powner ; // The owning control for this gesture
+    QStm_GestureListenerIf*  m_listener ;
+    bool                     m_gestureEnabled ;
+    bool                     m_loggingenabled ;
+    QStm_GestureRecognitionState m_state;
+};
+
+} // namespace
+
+
+#endif /* QSTMGESTURELISTENER_IF_H_ */