[vlc-devel] [PATCH 44/49] qml: avoid reloading pages completely when possible

[Pierre Lamot]

  this performs partial reload when navigating history rather than
  reloading the whole page
---
 .../gui/qt/qml/mediacenter/MCMainDisplay.qml  | 49 +++++++++----------
 .../gui/qt/qml/mediacenter/MCMusicDisplay.qml | 27 +++++++---
 modules/gui/qt/qml/utils/StackViewExt.qml     | 17 +++++++
 3 files changed, 59 insertions(+), 34 deletions(-)

diff --git a/modules/gui/qt/qml/mediacenter/MCMainDisplay.qml b/modules/gui/qt/qml/mediacenter/MCMainDisplay.qml
index 24345d17c8..2e29a70d15 100644
--- a/modules/gui/qt/qml/mediacenter/MCMainDisplay.qml
+++ b/modules/gui/qt/qml/mediacenter/MCMainDisplay.qml
@@ -34,6 +34,28 @@ Utils.NavigableFocusScope {
     property string view: ""
     property var viewProperties: ({})
 
+    onViewChanged: loadView()
+    onViewPropertiesChanged: loadView()
+    Component.onCompleted: loadView()
+
+    function loadView() {
+        var found = stackView.loadView(root.pageModel, root.view, root.viewProperties)
+
+        sourcesBanner.subTabModel = stackView.currentItem.tabModel
+        sourcesBanner.sortModel = stackView.currentItem.sortModel
+        sourcesBanner.contentModel = stackView.currentItem.contentModel
+        sourcesBanner.extraLocalActions = stackView.currentItem.extraLocalActions
+        // Restore sourcesBanner state
+        sourcesBanner.selectedIndex = pageModel.findIndex(function (e) {
+            return e.name === root.view
+        })
+        if (stackView.currentItem.pageModel !== undefined)
+            sourcesBanner.subSelectedIndex = stackView.currentItem.pageModel.findIndex(function (e) {
+                return e.name === stackView.currentItem.view
+            })
+    }
+
+
     Component {
         id: musicComp
         MCMusicDisplay {
@@ -129,17 +151,9 @@ Utils.NavigableFocusScope {
 
                     onItemClicked: {
                         sourcesBanner.subTabModel = undefined
-
                         var name = root.tabModel.get(index).name
-                        stackView.replace(root.pageModel[index].component)
-                        history.push(["mc", name], History.Stay)
-
-                        subTabModel = stackView.currentItem.tabModel
-                        sortModel = stackView.currentItem.sortModel
-                        contentModel = stackView.currentItem.contentModel
-                        extraLocalActions = stackView.currentItem.extraLocalActions
-
                         selectedIndex = index
+                        history.push(["mc", name], History.Go)
                     }
 
                     onSubItemClicked: {
@@ -197,23 +211,6 @@ Utils.NavigableFocusScope {
                             bottom: parent.bottom
                             right: playlist.visible ? playlist.left : parent.right
                         }
-
-                        Component.onCompleted: {
-                            var found = stackView.loadView(root.pageModel, root.view, root.viewProperties)
-                            sourcesBanner.subTabModel = stackView.currentItem.tabModel
-                            sourcesBanner.sortModel = stackView.currentItem.sortModel
-                            sourcesBanner.contentModel = stackView.currentItem.contentModel
-                            sourcesBanner.extraLocalActions = stackView.currentItem.extraLocalActions
-
-                            // Restore sourcesBanner state
-                            sourcesBanner.selectedIndex = pageModel.findIndex(function (e) {
-                                return e.name === root.view
-                            })
-                            if (stackView.currentItem.pageModel !== undefined)
-                                sourcesBanner.subSelectedIndex = stackView.currentItem.pageModel.findIndex(function (e) {
-                                    return e.name === stackView.currentItem.view
-                                })
-                        }
                     }
 
 
diff --git a/modules/gui/qt/qml/mediacenter/MCMusicDisplay.qml b/modules/gui/qt/qml/mediacenter/MCMusicDisplay.qml
index e97f116e76..68a2bd0384 100644
--- a/modules/gui/qt/qml/mediacenter/MCMusicDisplay.qml
+++ b/modules/gui/qt/qml/mediacenter/MCMusicDisplay.qml
@@ -37,14 +37,28 @@ Utils.NavigableFocusScope {
     property var sortModel
     property var contentModel
 
-    function loadIndex(index) {
-        stackView.replace(root.pageModel[index].component)
-        history.push(["mc", "music", root.pageModel[index].name], History.Stay)
-        stackView.focus = true
+    onViewChanged: loadView()
+    onViewProperties: loadView()
+    Component.onCompleted: loadView()
+
+    function loadView() {
+        var found = stackView.loadView(root.pageModel, view, viewProperties)
+        if (!found)
+            stackView.replace(root.pageModel[0].component)
         sortModel = stackView.currentItem.sortModel
         contentModel = stackView.currentItem.model
     }
 
+    //reset view
+    function loadDefaultView() {
+        root.view = "albums"
+        root.viewProperties= ({})
+    }
+
+    function loadIndex(index) {
+        history.push(["mc", "music", root.pageModel[index].name], History.Go)
+    }
+
     Component { id: albumComp; MusicAlbumsDisplay{ navigationParent: root } }
     Component { id: artistComp; MusicArtistsDisplay{ navigationParent: root } }
     Component { id: genresComp; MusicGenresDisplay{ navigationParent: root } }
@@ -92,12 +106,9 @@ Utils.NavigableFocusScope {
             Layout.margins: VLCStyle.margin_normal
             focus: true
 
-            Component.onCompleted: {
-                var found = stackView.loadView(root.pageModel, view, viewProperties)
+            onCurrentItemChanged: {
                 sortModel = stackView.currentItem.sortModel
                 contentModel = stackView.currentItem.model
-                if (!found)
-                    replace(pageModel[0].component)
             }
         }
     }
diff --git a/modules/gui/qt/qml/utils/StackViewExt.qml b/modules/gui/qt/qml/utils/StackViewExt.qml
index 7d988ad555..19554d09c7 100644
--- a/modules/gui/qt/qml/utils/StackViewExt.qml
+++ b/modules/gui/qt/qml/utils/StackViewExt.qml
@@ -24,6 +24,8 @@ import QtQuick.Controls 2.4
 StackView {
     id: root
 
+    property string _currentView: ""
+
     replaceEnter: Transition {
         PropertyAnimation {
             property: "opacity"
@@ -52,6 +54,19 @@ StackView {
      */
     function loadView(viewModel, view, viewProperties)
     {
+        if (view === _currentView) {
+            if (Object.keys(viewProperties).length === 0 && root.currentItem.hasOwnProperty("loadDefaultView") ) {
+                root.currentItem.loadDefaultView()
+            } else {
+                for ( var viewProp in viewProperties ) {
+                    if ( root.currentItem.hasOwnProperty(viewProp) ) {
+                        root.currentItem[viewProp] = viewProperties[viewProp]
+                    }
+                }
+            }
+            return true
+        }
+
         var found = false
         for (var tab = 0; tab < viewModel.length; tab++ )
         {
@@ -81,6 +96,8 @@ StackView {
         }
         if (!found)
             console.warn("unable to load view " + view)
+        else
+            _currentView = view
         return found
     }
 }
-- 
2.20.1