[gnome-shell/wip/paging-release: 13/93] PaginationScrollView: Added pan action

[Carlos Soriano <csoriano src gnome org>]

commit cf78debb0f92cd95789eea531fb72bc13e57c88d
Author: Carlos Soriano <carlos soriano89 gmail com>
Date:   Mon Aug 12 16:36:45 2013 +0200

    PaginationScrollView: Added pan action

 js/ui/appDisplay.js |   68 ++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 54 insertions(+), 14 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index e70646e..d69d010 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -276,6 +276,17 @@ const PaginationScrollView = new Lang.Class({
         this._parent = parent;
         
         this.connect('scroll-event', Lang.bind(this, this._onScroll));
+        
+        let panAction = new Clutter.PanAction({ interpolate: false });
+        panAction.connect('pan', Lang.bind(this, this._onPan));
+        panAction.connect('gesture-cancel', Lang.bind(this, function() {
+            this._goToNearestPage(Math.abs(this._panAction.get_velocity(0)[2]));
+        }));
+        panAction.connect('gesture-end', Lang.bind(this, function() {
+            this._goToNearestPage(Math.abs(this._panAction.get_velocity(0)[2]));
+        }));
+        this._panAction = panAction;
+        this.add_action(panAction);
     },
     
     vfunc_get_preferred_height: function (container, forWidht) {
@@ -325,12 +336,44 @@ const PaginationScrollView = new Lang.Class({
         return this._currentPage;
     },
     
+    _diffToPage: function (pageNumber) {
+        let currentScrollPosition = this.vscroll.adjustment.value;
+        return Math.abs(currentScrollPosition - this._pages._grid.getPagePosition(pageNumber)[1]);
+    },
+    
+    _nearestPage: function() {
+        let currentNearestPage = 0;
+        let diff = this._diffToPage(currentNearestPage);
+        let oldDiff = diff;
+        
+        while(diff <= oldDiff && currentNearestPage < (this._pages.nPages() - 1)) {
+            currentNearestPage++;
+            oldDiff = diff;
+            diff = this._diffToPage(currentNearestPage);            
+        }
+        if(diff > oldDiff)
+            currentNearestPage--;
+
+        return currentNearestPage; 
+    },
+
+    _goToNearestPage: function(velocity) {
+        this._parent.goToPage(this._nearestPage(), velocity);
+    },
+    
     _onScroll: function(actor, event) {
         let direction = event.get_scroll_direction();
+        let nextPage;
         if (direction == Clutter.ScrollDirection.UP)
-            this._parent.goToPage(this._currentPage - 1);
+            if(this._currentPage > 0) {
+                nextPage = this._currentPage - 1;
+                this._parent.goToPage(nextPage);
+            }
         if (direction == Clutter.ScrollDirection.DOWN)
-            this._parent.goToPage(this._currentPage + 1);
+            if(this._currentPage < (this.nPages() - 1)) {
+                nextPage = this._currentPage + 1;
+                this._parent.goToPage(nextPage);
+            }
     },
     
     addFolderPopup: function(popup) {
@@ -350,6 +393,13 @@ const PaginationScrollView = new Lang.Class({
             else
                 this._items[id].actor.opacity = 255;
         }
+    },
+    
+    _onPan: function(action) {
+        let [dist, dx, dy] = action.get_motion_delta(0);
+        let adjustment = this.vscroll.adjustment;
+        adjustment.value -= (dy / this.height) * adjustment.page_size;
+        return false;
     }
 });
 
@@ -492,16 +542,6 @@ const AllView = new Lang.Class({
 
         return false;
     },
-   
-    _onPan: function(action) {
-        /*
-        this._clickAction.release();
-
-        let [dist, dx, dy] = action.get_motion_delta(0);
-        let adjustment = this.actor.vscroll.adjustment;
-        adjustment.value -= (dy / this.actor.height) * adjustment.page_size;*/
-        return false;
-    },
 
     addApp: function(app) {
        let appIcon = this._paginationView._pages.addItem(app);
@@ -529,9 +569,9 @@ const AllView = new Lang.Class({
         this._paginationView._pages.loadGrid();
     },
     
-    goToPage: function(index) {
+    goToPage: function(index, velocity) {
         this._paginationIndicator.get_child_at_index(this._paginationView.currentPage()).set_checked(false);
-        this._paginationView.goToPage(index);
+        this._paginationView.goToPage(index, velocity);
         this._paginationIndicator.get_child_at_index(this._paginationView.currentPage()).set_checked(true);
     }
 });