path: root/recipes/efl1/etk/etk_scrolled_view_dragable_combined_bouncy.patch

Hi All,
    The attached patch lets etk_scrolled_view been dragable with 
pressing on the panel directly and drag. If you drag fast, after 
releasing the panel will still scrolling until it stop slowly.

Adding the following functions.
void            etk_scrolled_view_dragable_set(Etk_Scrolled_View 
*scrolled_view, Etk_Bool dragable);
Etk_Bool   etk_scrolled_view_dragable_get(Etk_Scrolled_View *scrolled_view);

additional functions for detail control. (Most user don't need them)
double        
etk_scrolled_view_drag_sample_interval_magic_set(Etk_Scrolled_View 
*scrolled_view,double interval);
double        
etk_scrolled_view_drag_sample_interval_magic_get(Etk_Scrolled_View 
*scrolled_view);
unsigned int etk_scrolled_view_drag_damping_magic_set(Etk_Scrolled_View 
*scrolled_view,unsigned int damping);
unsigned int etk_scrolled_view_drag_damping_magic_get(Etk_Scrolled_View 
*scrolled_view);

You can test this with etk_test after patching and adding two line in 
etk_test

Signed-off: Tick @ openmoko.org

Index: etk/src/lib/etk_scrolled_view.c
===================================================================
--- etk.orig/src/lib/etk_scrolled_view.c	2008-04-02 11:53:32.000000000 +0800
+++ etk/src/lib/etk_scrolled_view.c	2008-04-05 00:41:47.000000000 +0800
@@ -37,7 +37,15 @@
 static Etk_Bool _etk_scrolled_view_child_added_cb(Etk_Object *object, void *child, void *data);
 static Etk_Bool _etk_scrolled_view_child_removed_cb(Etk_Object *object, void *child, void *data);
 static Etk_Bool _etk_scrolled_view_child_scroll_size_changed_cb(Etk_Object *object, void *data);
+static int _etk_scrolled_view_motive_bounce(void *data); 
 
+
+static Etk_Bool _etk_scrolled_view_mouse_down(Etk_Object *object, Etk_Event_Mouse_Down *event, void *data); 
+static Etk_Bool _etk_scrolled_view_mouse_up(Etk_Object *object, Etk_Event_Mouse_Up *event, void *data);
+static Etk_Bool _etk_scrolled_view_mouse_click(Etk_Object *object, Etk_Event_Mouse_Up *event, void *data);
+static Etk_Bool _etk_scrolled_view_mouse_move(Etk_Object *object, Etk_Event_Mouse_Move *event, void *data); 
+
+static Etk_Bool _etk_scrolled_view_bar_mouse_down(Etk_Object *object, Etk_Event_Mouse_Down *event, void *data); 
 /**************************
  *
  * Implementation
@@ -173,6 +181,106 @@
       *vpolicy = scrolled_view ? scrolled_view->vpolicy : ETK_POLICY_AUTO;
 }
 
+/**
+ * @brief Set the scrolled view dragable or not
+ * @param scrolled_view a scrolled view
+ * @param dragable The scrolled view is dragable or not?
+ */ 
+void etk_scrolled_view_dragable_set(Etk_Scrolled_View *scrolled_view, Etk_Bool dragable) 
+{
+   if (!scrolled_view)
+      return;
+   scrolled_view->drag.dragable = dragable;
+}
+
+/**
+ * @brief Get the scrolled view dragable flag
+ * @param scrolled_view a scrolled view
+ * @return Returns ETK_TURE if the scrolled view is dragable
+ */
+Etk_Bool etk_scrolled_view_dragable_get(Etk_Scrolled_View *scrolled_view) 
+{
+   if (!scrolled_view)
+      return ETK_FALSE;
+   return scrolled_view->drag.dragable;
+}
+
+/**
+ * @brief Set the scrolled view boucy or not.
+ * @param scrolled_view  a scrolled view
+ * @param bouncy The scrolled view is bouncy or not (Default TRUE)
+ */ 
+void etk_scrolled_view_drag_bouncy_set(Etk_Scrolled_View *scrolled_view, Etk_Bool bouncy) 
+{
+   if (!scrolled_view)
+      return;
+   scrolled_view->drag.bouncy = bouncy;
+}
+
+/**
+ * @brief  Get the scrolled view bouncy flag
+ * @param scrolled_view  a scrolled view
+ * @return Returns ETK_TURE if the scrolled view is bouncy
+ */ 
+Etk_Bool etk_scrolled_view_drag_bouncy_get(Etk_Scrolled_View *scrolled_view) 
+{
+   if (!scrolled_view)
+      return ETK_FALSE;
+   return scrolled_view->drag.bouncy;
+}
+
+/**
+ * @brief Set the scrolled view sample interval to calculate the scrolling speed.
+ * @param scrolled_view a scrolled view
+ * @param interval The interval of sampling latest scrolling speed (minimial 0.2 second, default 0.5 second)
+ * @return Returns the actual sampling interval set. If scrolled_view is NULL returns 0.0f. 
+ */
+double etk_scrolled_view_drag_sample_interval_magic_set(Etk_Scrolled_View *scrolled_view,double interval) 
+{
+   if (!scrolled_view)
+      return 0.0f;
+   interval = interval >= 0.2f ? interval : 0.2f;
+   scrolled_view->drag.sample_magic = interval;
+   return scrolled_view->drag.sample_magic;
+}
+
+/**
+ * @brief Get the scrolled view sample interval to calculate the scrolling speed.
+ * @param scrolled_view a scrolled view
+ * @return Returns the sampling interval. If scrolled_view is NULL return 0.0f. 
+ */
+double etk_scrolled_view_drag_sample_interval_magic_get(Etk_Scrolled_View *scrolled_view)
+{
+   if (!scrolled_view)
+      return 0.0f;
+   return scrolled_view->drag.sample_magic;
+}
+
+/**
+ * @brief Set the damping magic number of a dragable scrolled view
+ * @param scrolled_view a scrolled view
+ * @param damping The damping factor of the dragable scrolled view (default 100)
+ * @return Returns the actual damping factor set
+ */ 
+unsigned int etk_scrolled_view_drag_damping_magic_set(Etk_Scrolled_View *scrolled_view,unsigned int damping)
+{
+   if (!scrolled_view)
+      return 0;
+   scrolled_view->drag.damping_magic = damping;
+   return scrolled_view->drag.damping_magic;
+}
+
+/**
+ * @brief Get the damping magic number of a dragable scrolled view
+ * @param scrolled_view a scrolled view
+ * @return Returns the actual damping factor
+ */ 
+unsigned int etk_scrolled_view_drag_damping_magic_get(Etk_Scrolled_View *scrolled_view) 
+{
+   if (!scrolled_view)
+      return 0;
+   return scrolled_view->drag.damping_magic;
+}
 
 /**************************
  *
@@ -189,6 +297,14 @@
    scrolled_view->hpolicy = ETK_POLICY_AUTO;
    scrolled_view->vpolicy = ETK_POLICY_AUTO;
 
+   scrolled_view->drag.bar_pressed = ETK_FALSE;
+   scrolled_view->drag.dragable    = ETK_FALSE;
+   scrolled_view->drag.bouncy      = ETK_TRUE;
+
+   // FIXME This can be put in etk_config (Make whole system be configured)
+   etk_scrolled_view_drag_sample_interval_magic_set(scrolled_view,0.5f);
+   etk_scrolled_view_drag_damping_magic_set(scrolled_view,100);
+
    scrolled_view->hscrollbar = etk_hscrollbar_new(0.0, 0.0, 0.0, 12.0, 50.0, 0.0);
    etk_widget_theme_parent_set(scrolled_view->hscrollbar, ETK_WIDGET(scrolled_view));
    etk_widget_parent_set(scrolled_view->hscrollbar, ETK_WIDGET(scrolled_view));
@@ -205,11 +321,18 @@
    ETK_WIDGET(scrolled_view)->size_allocate = _etk_scrolled_view_size_allocate;
 
    etk_signal_connect_by_code(ETK_WIDGET_KEY_DOWN_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_key_down_cb), NULL);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_DOWN_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_mouse_down), &scrolled_view->drag);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_UP_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_mouse_up), &scrolled_view->drag);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_CLICK_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_mouse_click), &scrolled_view->drag);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_MOVE_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_mouse_move), &scrolled_view->drag);
    etk_signal_connect_by_code(ETK_WIDGET_MOUSE_WHEEL_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_mouse_wheel), NULL);
    etk_signal_connect_by_code(ETK_CONTAINER_CHILD_ADDED_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_child_added_cb), NULL);
    etk_signal_connect_by_code(ETK_CONTAINER_CHILD_REMOVED_SIGNAL, ETK_OBJECT(scrolled_view), ETK_CALLBACK(_etk_scrolled_view_child_removed_cb), NULL);
    etk_signal_connect_by_code(ETK_RANGE_VALUE_CHANGED_SIGNAL, ETK_OBJECT(scrolled_view->hscrollbar), ETK_CALLBACK(_etk_scrolled_view_hscrollbar_value_changed_cb), scrolled_view);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_DOWN_SIGNAL, ETK_OBJECT(scrolled_view->hscrollbar), ETK_CALLBACK(_etk_scrolled_view_bar_mouse_down), scrolled_view);
    etk_signal_connect_by_code(ETK_RANGE_VALUE_CHANGED_SIGNAL, ETK_OBJECT(scrolled_view->vscrollbar), ETK_CALLBACK(_etk_scrolled_view_vscrollbar_value_changed_cb), scrolled_view);
+   etk_signal_connect_by_code(ETK_WIDGET_MOUSE_DOWN_SIGNAL, ETK_OBJECT(scrolled_view->vscrollbar), ETK_CALLBACK(_etk_scrolled_view_bar_mouse_down), scrolled_view);
+
 }
 
 /* Sets the property whose id is "property_id" to the value "value" */
@@ -390,6 +513,94 @@
    etk_widget_size_allocate(child, child_geometry);
 }
 
+/* Check if reaching the boundary */
+static inline double _etk_scrolled_view_bounce_check (Etk_Range * range, double delta,double v) 
+{
+   double pos = (range->value + delta);
+   if (pos <= range->lower) 
+   {
+      pos = range->lower + (range->lower - pos);
+      v *= -1;
+   }
+   etk_range_value_set(range, pos);
+   if (pos > range->value) 
+      v *= -1;
+   return v;
+}
+
+/* Animator for inertial scrolling */
+static int _etk_scrolled_view_motive_bounce(void *data) 
+{
+   Etk_Scrolled_View *scrolled_view = ETK_SCROLLED_VIEW(data);
+   struct Etk_Scrolled_View_Mouse_Drag *drag;
+   Etk_Range *vscrollbar_range;
+   Etk_Range *hscrollbar_range;
+   double delta_time;
+   double delta_V;
+   double delta_x;
+   double delta_y;
+   if (!scrolled_view) 
+      return 0;
+   drag = &scrolled_view->drag;
+   if (drag->mouse_down) 
+      return 0;
+
+   // Using trapezoid method to calculate the distance. 
+   delta_time = ecore_time_get() - drag->timestamp;
+   delta_V = delta_time * (drag->damping_magic + abs(drag->Vx)+ abs(drag->Vy))/2;
+   delta_time = delta_time < 0.01f ? 0.01f: delta_time;
+
+   if (drag->Vx < delta_V && drag->Vx > -delta_V) 
+   {
+      delta_x = 0;
+      drag->Vx = 0;
+   } 
+   else if (drag->Vx > 0)
+   {
+      delta_x = ((drag->Vx * 2) - delta_V) * delta_time / 2;
+      drag->Vx = drag->Vx - delta_V;
+   } 
+   else 
+   {
+      delta_x = ((drag->Vx * 2) + delta_V) * delta_time / 2;
+      drag->Vx = drag->Vx +  delta_V;
+   }
+
+   if (drag->Vy < delta_V && drag->Vy > -delta_V) 
+   {
+      drag->Vy = 0;
+      delta_y = 0;
+   } 
+   else if(drag->Vy > 0)
+   {
+      delta_y = ((drag->Vy * 2) - delta_V) * delta_time / 2;
+      drag->Vy = drag->Vy - delta_V;
+   } else 
+   {
+      delta_y = ((drag->Vy * 2) + delta_V) * delta_time / 2;
+      drag->Vy = drag->Vy + delta_V;
+   }
+
+   if (drag->Vx == 0 && drag->Vy == 0) 
+      return 0;
+
+   vscrollbar_range = ETK_RANGE(scrolled_view->vscrollbar);
+   hscrollbar_range = ETK_RANGE(scrolled_view->hscrollbar);
+   if (drag->bouncy)  
+   {
+      drag->Vx = _etk_scrolled_view_bounce_check(hscrollbar_range, delta_x, drag->Vx);
+      drag->Vy = _etk_scrolled_view_bounce_check(vscrollbar_range, delta_y, drag->Vy);
+   }
+   else 
+   {
+      drag->Vx = drag->Vx == _etk_scrolled_view_bounce_check(hscrollbar_range, delta_x, drag->Vx) ? drag->Vx : 0.0f;
+      drag->Vy = drag->Vy == _etk_scrolled_view_bounce_check(vscrollbar_range, delta_y, drag->Vy) ? drag->Vy : 0.0f;
+   }
+   drag->timestamp = ecore_time_get();
+   return 1;
+}
+
+
 /**************************
  *
  * Callbacks and handlers
@@ -431,6 +642,135 @@
    return propagate;
 }
 
+/* Called when mouse button has been pressed down */
+static Etk_Bool _etk_scrolled_view_mouse_down(Etk_Object *object, Etk_Event_Mouse_Down *event, void *data) 
+{
+   Etk_Scrolled_View *scrolled_view;
+   Etk_Range *vscrollbar_range;
+   Etk_Range *hscrollbar_range;
+   struct Etk_Scrolled_View_Mouse_Drag *drag = (struct Etk_Scrolled_View_Mouse_Drag *) data;
+
+   if (!(scrolled_view = ETK_SCROLLED_VIEW(object)))
+      return ETK_FALSE;
+
+   if (!drag->dragable) 
+      return ETK_FALSE;
+
+   if (!drag->mouse_down && event->button) 
+   {
+      vscrollbar_range = ETK_RANGE(scrolled_view->vscrollbar);
+      hscrollbar_range = ETK_RANGE(scrolled_view->hscrollbar);
+      drag->mouse_down = ETK_TRUE;
+      drag->timestamp = ecore_time_get(); 
+      drag->old_timestamp = 0.0f;
+      drag->position = event->widget;
+      drag->bar_position.x = hscrollbar_range->value;
+      drag->bar_position.y = vscrollbar_range->value;
+   }
+   return ETK_FALSE;
+}
+
+/* Called when mouse is dragging */
+static Etk_Bool _etk_scrolled_view_mouse_move(Etk_Object *object, Etk_Event_Mouse_Move *event, void *data) 
+{
+   Etk_Scrolled_View *scrolled_view;
+   Etk_Range *vscrollbar_range;
+   Etk_Range *hscrollbar_range;
+   double delta_time;
+   struct Etk_Scrolled_View_Mouse_Drag *drag = (struct Etk_Scrolled_View_Mouse_Drag *) data;
+
+   if (!(scrolled_view = ETK_SCROLLED_VIEW(object)))
+      return ETK_FALSE;
+
+   if (!drag->dragable)
+      return ETK_FALSE;
+
+   if (!drag->mouse_down) 
+      return ETK_FALSE;
+
+   if (!event->buttons) 
+      return ETK_FALSE;
+
+   vscrollbar_range = ETK_RANGE(scrolled_view->vscrollbar);
+   hscrollbar_range = ETK_RANGE(scrolled_view->hscrollbar);
+   if (drag->scroll_flag == 0) 
+   {
+         drag->scroll_flag = (event->cur.widget.y - drag->position.y)/vscrollbar_range->step_increment || (event->cur.widget.x - drag->position.x)/hscrollbar_range->step_increment;
+   }
+
+   if (drag->scroll_flag) 
+   {
+      if (drag->bar_pressed==ETK_FALSE) 
+      {
+         etk_range_value_set(vscrollbar_range, vscrollbar_range->value - (event->cur.widget.y - drag->position.y));
+         etk_range_value_set(hscrollbar_range, hscrollbar_range->value - (event->cur.widget.x - drag->position.x));
+      }
+      drag->position  = event->cur.widget;
+      delta_time = ecore_time_get() - drag->timestamp;
+      // in case delta_time is zero
+      delta_time = delta_time == 0.0f ? drag->sample_magic : delta_time;
+      if (delta_time > drag->sample_magic || drag->old_timestamp == 0) 
+      {
+         drag->old_timestamp = drag->timestamp;
+         drag->timestamp = ecore_time_get();
+         drag->Vx = (hscrollbar_range->value - drag->bar_position.x) / delta_time;
+         drag->Vy = (vscrollbar_range->value - drag->bar_position.y) / delta_time;
+         drag->bar_position.x = hscrollbar_range->value;
+         drag->bar_position.y = vscrollbar_range->value;
+      }
+      return ETK_TRUE;
+   }
+   return ETK_FALSE;
+}
+
+/* Called when mouse button has been released */
+static Etk_Bool _etk_scrolled_view_mouse_up(Etk_Object *object, Etk_Event_Mouse_Up *event, void *data) 
+{
+   Etk_Scrolled_View *scrolled_view;
+   struct Etk_Scrolled_View_Mouse_Drag *drag = (struct Etk_Scrolled_View_Mouse_Drag *) data;
+
+   if (!(scrolled_view = ETK_SCROLLED_VIEW(object)))
+      return ETK_FALSE;
+
+   if (!drag->dragable) 
+      return ETK_FALSE;
+
+   if (!drag->mouse_down) 
+      return ETK_FALSE;
+
+   if (drag->bar_pressed == ETK_TRUE) 
+   {
+      drag->bar_pressed = ETK_FALSE;
+      return ETK_FALSE;
+   }
+
+   drag->mouse_down = ETK_FALSE;
+
+   if (drag->scroll_flag) 
+   {
+      drag->timestamp = ecore_time_get();
+      ecore_animator_add(&_etk_scrolled_view_motive_bounce, scrolled_view);
+      return ETK_TRUE;
+   }
+   return ETK_FALSE;
+}
+
+/* Called when mouse button has been clicked */
+static Etk_Bool _etk_scrolled_view_mouse_click (Etk_Object *object, Etk_Event_Mouse_Up *event, void *data) 
+{
+   Etk_Scrolled_View *scrolled_view;
+   struct Etk_Scrolled_View_Mouse_Drag *drag = (struct Etk_Scrolled_View_Mouse_Drag *) data;
+   if (!(scrolled_view = ETK_SCROLLED_VIEW(object)))
+      return ETK_TRUE;
+
+   if (drag->scroll_flag) 
+   {
+      drag->scroll_flag = 0;
+      return ETK_TRUE;
+   }
+   return ETK_FALSE;
+}
+
 /* Called when the user wants to scroll the scrolled view with the mouse wheel */
 static Etk_Bool _etk_scrolled_view_mouse_wheel(Etk_Object *object, Etk_Event_Mouse_Wheel *event, void *data)
 {
@@ -458,6 +798,18 @@
    return ETK_TRUE;
 }
 
+/* Called when dragging on the scrollbar */
+static Etk_Bool _etk_scrolled_view_bar_mouse_down(Etk_Object *object, Etk_Event_Mouse_Down *event, void *data) 
+{
+   Etk_Scrolled_View *scrolled_view;
+   Etk_Widget *child;
+   if (!(scrolled_view = ETK_SCROLLED_VIEW(data)) || !(child = ETK_BIN(scrolled_view)->child) || !child->scroll)
+      return ETK_FALSE;
+   scrolled_view->drag.bar_pressed = ETK_TRUE;
+   return ETK_FALSE;
+}
+
+
 /* Called when the value of the vscrollbar has changed */
 static Etk_Bool _etk_scrolled_view_vscrollbar_value_changed_cb(Etk_Object *object, double value, void *data)
 {
Index: etk/src/lib/etk_scrolled_view.h
===================================================================
--- etk.orig/src/lib/etk_scrolled_view.h	2008-04-02 11:53:32.000000000 +0800
+++ etk/src/lib/etk_scrolled_view.h	2008-04-05 00:03:31.000000000 +0800
@@ -33,9 +33,24 @@
    ETK_POLICY_AUTO,     /**< The scrollbar is shown and hidden automatically whether or not the child can fit
                          * entirely in the scrolled view */
    ETK_POLICY_SHOW,     /**< The scrollbar is always visible */
-   ETK_POLICY_HIDE      /**< The scrollbar is always hidden */
+   ETK_POLICY_HIDE,     /**< The scrollbar is always hidden */
 } Etk_Scrolled_View_Policy;
 
+struct Etk_Scrolled_View_Mouse_Drag 
+{
+   Etk_Bool mouse_down;
+   Etk_Bool bar_pressed;
+   Etk_Bool dragable;
+   Etk_Bool bouncy;
+   int scroll_flag;
+   Etk_Position position;
+   Etk_Position bar_position;
+   double sample_magic;
+   unsigned int damping_magic;
+   double timestamp;
+   double old_timestamp;
+   double Vx,Vy;
+};
 
 /**
  * @brief @widget The structure of a scrolled view
@@ -52,9 +67,12 @@
 
    Etk_Scrolled_View_Policy hpolicy;
    Etk_Scrolled_View_Policy vpolicy;
+
+   struct Etk_Scrolled_View_Mouse_Drag drag;
 };
 
 
+
 Etk_Type   *etk_scrolled_view_type_get(void);
 Etk_Widget *etk_scrolled_view_new(void);
 
@@ -63,6 +81,14 @@
 void        etk_scrolled_view_add_with_viewport(Etk_Scrolled_View *scrolled_view, Etk_Widget *child);
 void        etk_scrolled_view_policy_set(Etk_Scrolled_View *scrolled_view, Etk_Scrolled_View_Policy hpolicy, Etk_Scrolled_View_Policy vpolicy);
 void        etk_scrolled_view_policy_get(Etk_Scrolled_View *scrolled_view, Etk_Scrolled_View_Policy *hpolicy, Etk_Scrolled_View_Policy *vpolicy);
+void        etk_scrolled_view_dragable_set(Etk_Scrolled_View *scrolled_view, Etk_Bool dragable);
+Etk_Bool    etk_scrolled_view_dragable_get(Etk_Scrolled_View *scrolled_view);
+void        etk_scrolled_view_drag_bouncy_set(Etk_Scrolled_View *scrolled_view, Etk_Bool bouncy);
+Etk_Bool    etk_scrolled_view_drag_bouncy_get(Etk_Scrolled_View *scrolled_view);
+double      etk_scrolled_view_drag_sample_interval_magic_set(Etk_Scrolled_View *scrolled_view,double interval);
+double      etk_scrolled_view_drag_sample_interval_magic_get(Etk_Scrolled_View *scrolled_view);
+unsigned int etk_scrolled_view_drag_damping_magic_set(Etk_Scrolled_View *scrolled_view,unsigned int damping);
+unsigned int etk_scrolled_view_drag_damping_magic_get(Etk_Scrolled_View *scrolled_view);
 
 /** @} */