[gnome-shell/gbsneto/icon-grid-dnd: 2/10] appIcon: Hide itself when starting drag

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 749ce25ac90eae442f90acf5b37c34c7607ebe77
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Jul 4 18:39:13 2019 -0300

    appIcon: Hide itself when starting drag
    
    As per design direction, hide the app icon when starting
    dragging it, and show it again if the drop is accepted.
    Clutter takes care of animating the rest of icon positions
    through implicit animations.
    
    Add a new icon parameter 'hideWhileDragging', that is false
    by default, so as to preserve the current behavior or the
    Dash and the search results.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603

 js/ui/appDisplay.js | 54 ++++++++++++++++++++++++++++++++++++-----------------
 js/ui/dash.js       |  2 ++
 2 files changed, 39 insertions(+), 17 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index ac5e5a325..e04383aa2 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -474,7 +474,8 @@ var AllView = class AllView extends BaseAppView {
             let app = appSys.lookup_app(appId);
 
             let icon = new AppIcon(app, this,
-                                   { isDraggable: favoritesWritable });
+                                   { isDraggable: favoritesWritable,
+                                     hideWhileDragging: true });
             newApps.push(icon);
         });
 
@@ -839,10 +840,6 @@ var AllView = class AllView extends BaseAppView {
     handleDragOver(source, actor, x, y, time) {
         [x, y] = this._transformToGridCoordinates(x, y);
 
-        let sourceIndex = -1;
-        if (source.parentView == this)
-            sourceIndex = this._allItems.indexOf(source);
-
         let [index, dragLocation] = this.canDropAt(x, y);
 
         this.removeNudges();
@@ -850,9 +847,7 @@ var AllView = class AllView extends BaseAppView {
             this._schedulePopdown();
 
         if (index != -1) {
-            if (sourceIndex == -1 || (index != sourceIndex && index != sourceIndex + 1))
-                this.nudgeItemsAtIndex(index, dragLocation);
-
+            this.nudgeItemsAtIndex(index, dragLocation);
             return DND.DragMotionResult.MOVE_DROP;
         }
 
@@ -872,6 +867,15 @@ var AllView = class AllView extends BaseAppView {
             source = this._items[source.id];
         }
 
+        // AppIcon hides itself, show it again
+        source.actor.show();
+
+        // When moving to a position forward, the index will be misadjusted by
+        // one, because the original actor is hidden. Adjust it back.
+        let sourceIndex = this._allItems.indexOf(source);
+        if (sourceIndex != -1 && index > sourceIndex)
+            index++;
+
         this.moveItem(source, index);
         this.removeNudges();
         return true;
@@ -1330,8 +1334,7 @@ var FolderView = class FolderView extends BaseAppView {
 
         this._folderIcon._parentView.removeNudges();
         this.removeNudges();
-        if (index != -1 && index != sourceIndex && index != sourceIndex + 1)
-            this.nudgeItemsAtIndex(index, dragLocation);
+        this.nudgeItemsAtIndex(index, dragLocation);
 
         return DND.DragMotionResult.MOVE_DROP;
     }
@@ -1340,8 +1343,17 @@ var FolderView = class FolderView extends BaseAppView {
         [x, y] = this._transformToGridCoordinates(x, y);
 
         let [index, dragLocation] = this.canDropAt(x, y);
+        let sourceIndex = this._allItems.indexOf(source);
         let success = index != -1;
 
+        // AppIcon hides itself, show it again
+        source.actor.show();
+
+        // When moving to a position forward, the index will be misadjusted by
+        // one, because the original actor is hidden. Adjust it back.
+        if (sourceIndex != -1 && index > sourceIndex)
+            index++;
+
         if (success)
             this.moveItem(source, index);
 
@@ -1395,7 +1407,7 @@ var FolderView = class FolderView extends BaseAppView {
             if (!app.get_app_info().should_show())
                 return;
 
-            let icon = new AppIcon(app, this);
+            let icon = new AppIcon(app, this, { hideWhileDragging: true });
             apps.push(icon);
         };
 
@@ -1552,8 +1564,11 @@ var FolderIcon = class FolderIcon {
     acceptDrop(source, actor, x, y, time) {
         this._unscheduleOpenPopup();
 
-        if (!this._canDropAt(source))
+        if (!this._canDropAt(source)) {
+            // AppIcon hides itself, show it again
+            source.actor.show();
             return true;
+        }
 
         let app = source.app;
         let folderApps = this._folder.get_strv('apps');
@@ -1860,10 +1875,14 @@ var AppIcon = class AppIcon {
         this._scaleInId = 0;
 
         // Get the isDraggable property without passing it on to the BaseIcon:
-        let appIconParams = Params.parse(iconParams, { isDraggable: true }, true);
+        let appIconParams = Params.parse(iconParams, { isDraggable: true,
+                                                       hideWhileDragging: false, }, true);
         let isDraggable = appIconParams['isDraggable'];
         delete iconParams['isDraggable'];
 
+        let hideWhileDragging = appIconParams['hideWhileDragging'];
+        delete iconParams['hideWhileDragging'];
+
         iconParams['createIcon'] = this._createIcon.bind(this);
         iconParams['setSizeManually'] = true;
         this.icon = new IconGrid.BaseIcon(app.get_name(), iconParams);
@@ -1884,18 +1903,19 @@ var AppIcon = class AppIcon {
             this._draggable = DND.makeDraggable(this.actor);
             this._draggable.connect('drag-begin', () => {
                 this._dragging = true;
-                this.actor.opacity = 0;
+                if (hideWhileDragging)
+                    this.actor.hide();
                 this._removeMenuTimeout();
                 Main.overview.beginItemDrag(this);
             });
             this._draggable.connect('drag-cancelled', () => {
                 this._dragging = false;
-                this.actor.opacity = 255;
                 Main.overview.cancelledItemDrag(this);
             });
-            this._draggable.connect('drag-end', () => {
+            this._draggable.connect('drag-end', (source, time, success) => {
                 this._dragging = false;
-                this.actor.opacity = 255;
+                if (!success && hideWhileDragging)
+                    this.actor.show();
                 Main.overview.endItemDrag(this);
             });
         }
diff --git a/js/ui/dash.js b/js/ui/dash.js
index bde0fe094..b7a1d33e6 100644
--- a/js/ui/dash.js
+++ b/js/ui/dash.js
@@ -871,6 +871,8 @@ var Dash = class Dash {
     acceptDrop(source, actor, x, y, time) {
         let app = getAppFromSource(source);
 
+        source.actor.show();
+
         // Don't allow favoriting of transient apps
         if (app == null || app.is_window_backed()) {
             return false;