a new central LauncherDragManager.qml

a central place to manage the dragging around of launchers
and reparent between their 3 possible parents

containments/homescreen2/package/contents/ui/launcher/Delegate.qml

@@ -33,9 +33,7 @@ ContainmentLayoutManager.ItemContainer {
     z: dragging ? 1 : 0
 
     property var modelData: typeof model !== "undefined" ? model : null
-    property ContainmentLayoutManager.ItemContainer beforeItem
     property Item container
-    property ContainmentLayoutManager.ItemContainer before
 
     leftPadding: units.smallSpacing * 2
     topPadding: units.smallSpacing * 2
@@ -47,72 +45,53 @@ ContainmentLayoutManager.ItemContainer {
     editModeCondition: ContainmentLayoutManager.ItemContainer.AfterPressAndHold//model.ApplicationOnDesktopRole ? ContainmentLayoutManager.ItemContainer.AfterPressAndHold: ContainmentLayoutManager.ItemContainer.Manual
     onEditModeChanged: {//FIXME: remove
         plasmoid.editMode = editMode
-        if (!editMode) {
-            root.forceLayout();
-        }
     }
     onDragActiveChanged: {
         if (dragActive) {
-            if (container) {
+            launcherDragManager.showSpacer(delegate, 0, 0);
-                container.showSpacerBefore(delegate);
+print("AAAH, BENGALAAAAH")
-            }
             return;
         }
         
         plasmoid.editMode = false;
         editMode = false;
-        if (container) {
-            container.forceLayout();
-            container.hideSpacer();
-        }
-    }
-
-    onParentChanged: {
-        if (container) {
-            plasmoid.nativeInterface.orderItems(delegate, before);
-        }
     }
 
     onUserDrag: {
        // newPosition
         var newRow = 0;
 
+        var newContainer = launcherDragManager.containerForItem(delegate, dragCenter.x, dragCenter.y);
+
         // Put it in the favorites strip
-        if (favoriteStrip.contains(favoriteStrip.mapFromItem(delegate, dragCenter.x, dragCenter.y))) {
+        if (newContainer == favoriteStrip) {
             var pos = favoriteStrip.mapFromItem(delegate, 0, 0);
             newRow = Math.floor((pos.x + dragCenter.x) / delegate.width);
-            before = favoriteStrip.flow.childAt(delegate.x + dragCenter.x, delegate.y + dragCenter.y);
 
             plasmoid.nativeInterface.applicationListModel.setFavoriteItem(index, true);
 
 
         // Put it on desktop
-        } else if (appletsLayout.contains(appletsLayout.mapFromItem(delegate, dragCenter.x, dragCenter.y))) {
+        } else if (newContainer == appletsLayout) {
             var pos = appletsLayout.mapFromItem(delegate, 0, 0);
             plasmoid.nativeInterface.applicationListModel.setDesktopItem(index, true);
             delegate.x = pos.x
             delegate.y = pos.y
-            before = null;
             return;
     
         // Put it in the general view
         } else {
+            newRow = Math.round(newContainer.flow.width / delegate.width) * Math.floor((delegate.y + dragCenter.y) / delegate.height) + Math.floor((delegate.x + dragCenter.x) / delegate.width) + favoriteStrip.count;
+
             plasmoid.nativeInterface.applicationListModel.setFavoriteItem(index, false);
             plasmoid.nativeInterface.applicationListModel.setDesktopItem(index, false);
-
-            newRow = Math.round(applicationsFlow.width / delegate.width) * Math.floor((delegate.y + dragCenter.y) / delegate.height) + Math.floor((delegate.x + dragCenter.x) / delegate.width) + favoriteStrip.count;
-            before = applicationsFlow.childAt(delegate.x + dragCenter.x, delegate.y + dragCenter.y);
         }
 
+        launcherDragManager.showSpacer(delegate, dragCenter.x, dragCenter.y);
+
         plasmoid.nativeInterface.applicationListModel.setDesktopItem(index, false);
 
         plasmoid.nativeInterface.applicationListModel.moveItem(modelData.index, newRow);
-
-        if (container) {
-            container.showSpacerBefore(before);
-        }
-
-        //delegate.x = newPosition.x;
     }
 
     contentItem: MouseArea {

containments/homescreen2/package/contents/ui/launcher/FavoriteStrip.qml

@@ -29,8 +29,6 @@ import org.kde.kquickcontrolsaddons 2.0
 LauncherContainer {
     id: root
 
-    property Controls.Control launcherGrid
-
     readonly property int count: flow.width / launcherGrid.cellWidth
 
     flow.flow: Flow.TopToBottom

containments/homescreen2/package/contents/ui/launcher/LauncherContainer.qml

@@ -25,6 +25,7 @@ import org.kde.plasma.core 2.0 as PlasmaCore
 import org.kde.plasma.components 2.0 as PlasmaComponents
 import org.kde.kquickcontrolsaddons 2.0
 
+import org.kde.plasma.private.containmentlayoutmanager 1.0 as ContainmentLayoutManager 
 
 Controls.Control {
     id: root
@@ -32,21 +33,12 @@ Controls.Control {
     readonly property int reservedSpaceForLabel: metrics.height
     property int availableCellHeight: units.iconSizes.huge + reservedSpaceForLabel
 
+    property ContainmentLayoutManager.AppletsLayout appletsLayout
+    property Controls.Control launcherGrid
+    property Controls.Control favoriteStrip
+
     property alias flow: applicationsFlow
 
-    function forceLayout() {
-        applicationsFlow.forceLayout();
-    }
-
-    function showSpacerBefore(item) {
-        spacer.parent = applicationsFlow
-        plasmoid.nativeInterface.orderItems(spacer, item);
-    }
-
-    function hideSpacer() {
-        spacer.parent = flowParent;
-    }
-
     implicitWidth: contentItem.implicitWidth + frame.margins.top + frame.margins.bottom
     implicitHeight: contentItem.implicitHeight + frame.margins.top + frame.margins.bottom
 

containments/homescreen2/package/contents/ui/launcher/LauncherDragManager.qml

@@ -0,0 +1,139 @@
+/*
+ *   Copyright 2019 Marco Martin <mart@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2, or
+ *   (at your option) any later version.
+ *
+ *   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 General Public License for more details
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this program; if not, write to the
+ *   Free Software Foundation, Inc.,
+ *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+import QtQuick 2.4
+
+import org.kde.plasma.private.containmentlayoutmanager 1.0 as ContainmentLayoutManager 
+
+QtObject {
+    id: root
+
+    property ContainmentLayoutManager.AppletsLayout appletsLayout
+    property LauncherGrid launcherGrid
+    property FavoriteStrip favoriteStrip
+
+    readonly property Item spacer: Item {
+        width: units.gridUnit * 4
+        height: width
+    }
+
+    function raiseContainer(container) {
+        container.z = 1;
+
+        if (container == appletsLayout) {
+            launcherGrid.z = 0;
+            favoriteStrip.z = 0;
+        } else if (container == favoriteStrip) {
+            appletsLayout.z = 0;
+            launcherGrid.z = 0;
+        } else {
+            appletsLayout.z = 0;
+            favoriteStrip.z = 0;
+        } 
+    }
+
+    function containerForItem(item, dragCenterX, dragCenterY) {
+        if (favoriteStrip.contains(favoriteStrip.mapFromItem(item, dragCenterX, dragCenterY))) {
+            return favoriteStrip;
+        } else if (appletsLayout.contains(appletsLayout.mapFromItem(item, dragCenterX, dragCenterY))) {
+            return appletsLayout;
+        } else {
+            return launcherGrid;
+        }
+    }
+
+    function changeContainer(item, container) {
+        var pos = container.contentItem.mapFromItem(item, 0, 0);
+
+        if (container == appletsLayout) {
+            item.parent = container;
+        } else {
+            item.parent = container.contentItem;
+        }
+
+        item.x = pos.x;
+        item.y = pos.y;
+    }
+
+    function putInContainerLayout(item, container) {
+        var pos = container.contentItem.mapFromItem(item, 0, 0);
+
+        if (container == appletsLayout) {
+            item.parent = container;
+        } else {
+            item.parent = container.flow;
+        }
+
+        item.x = pos.x;
+        item.y = pos.y;
+    }
+
+    function showSpacer(item, dragCenterX, dragCenterY) {
+        var container = containerForItem(item, dragCenterX, dragCenterY);
+
+        raiseContainer(container);
+
+        var child = container.flow.childAt(item.x + dragCenterX, item.y + dragCenterX);
+        if (!child) {
+            return;
+        }
+
+        changeContainer(item, container);
+        if (container == appletsLayout) {
+            return;
+        }
+
+        spacer.visible = false;
+        spacer.parent = container.flow
+
+        if (item.x + dragCenterX < child.x + child.width / 2) {
+            plasmoid.nativeInterface.orderItems(spacer, child);
+        } else {
+            plasmoid.nativeInterface.orderItems(child, spacer);
+        }
+        spacer.visible = true;
+    }
+
+    function positionItem(item, dragCenterX, dragCenterY) {
+        var container = containerForItem(item, dragCenterX, dragCenterY);
+
+        raiseContainer(container);
+
+        if (container == appletsLayout) {
+            return;
+        }
+
+        spacer.visible = false;
+        spacer.parent = container.contentItem;
+
+        var child = container.flow.childAt(item.x + dragCenterX, item.y + dragCenterX);
+        if (!child) {
+            return;
+        }
+
+        putInContainerLayout(item, container);
+        if (item.x + dragCenterX < child.x + child.width / 2) {
+            plasmoid.nativeInterface.orderItems(item, child);
+        } else {
+            plasmoid.nativeInterface.orderItems(child, item);
+        }
+    }
+}
+
+

containments/homescreen2/package/contents/ui/launcher/LauncherGrid.qml

@@ -37,9 +37,6 @@ LauncherContainer {
     readonly property int cellWidth: root.flow.width / Math.floor(root.flow.width / ((availableCellHeight - reservedSpaceForLabel) + units.smallSpacing*4))
     readonly property int cellHeight: availableCellHeight - topPadding
 
-    property ContainmentLayoutManager.AppletsLayout appletsLayout
-    property FavoriteStrip favoriteStrip
-
 
     Repeater {
         model: plasmoid.nativeInterface.applicationListModel
@@ -58,33 +55,18 @@ LauncherContainer {
             }
             parent: {
                 if (model.ApplicationOnDesktopRole) {
-                    var pos = appletsLayout.mapFromItem(delegate, 0, 0);
-                    x = pos.x;
-                    y = pos.y;
                     return appletsLayout;
                 }
                 if (model.ApplicationFavoriteRole) {
                     if (editMode) {
-                        var pos = favoriteStrip.contentItem.mapFromItem(delegate, 0, 0);
-                        x = pos.x;
-                        y = pos.y;
                         return favoriteStrip.contentItem;
                     } else {
-                        var pos = favoriteStrip.flow.mapFromItem(delegate, 0, 0);
-                        x = pos.x;
-                        y = pos.y;
                         return favoriteStrip.flow;
                     }
                 }
                 if (editMode) {
-                    var pos = flowParent.mapFromItem(delegate, 0, 0);
-                    x = pos.x;
-                    y = pos.y;
                     return flowParent;
                 } else {
-                    var pos = root.flow.mapFromItem(delegate, 0, 0);
-                    x = pos.x;
-                    y = pos.y;
                     return root.flow;
                 }
             }

containments/homescreen2/package/contents/ui/main.qml

@@ -49,6 +49,13 @@ Text {
         }
     }
 
+    Launcher.LauncherDragManager {
+        id: launcherDragManager
+        appletsLayout: appletsLayout
+        launcherGrid: launcher
+        favoriteStrip: favoriteStrip
+    }
+
     Flickable {
         id: mainFlickable
         anchors {
@@ -152,6 +159,7 @@ Text {
                     placeHolder: ContainmentLayoutManager.PlaceHolder {}
                 }
             }
+
             Launcher.LauncherGrid {
                 id: launcher
                 Layout.fillWidth: true
@@ -161,6 +169,7 @@ Text {
             }
         }
     }
+
     Launcher.FavoriteStrip {
         id: favoriteStrip
         anchors.horizontalCenter: parent.horizontalCenter