From 2e6fd8b73024f9ab220db9c82b83d0b9914a69e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20Dre=C3=9Fler?= <verdre@v0yd.nl>
Date: Fri, 24 Jun 2022 13:01:16 +0200
Subject: [PATCH] iconGrid: Return page and position for drop targets instead
 of items

Returning a page and a position for the drop target seems more
straightforward than returning an actual grid item in getDropTarget().

With the next commit, this will allow us to throw away drop targets that
are not on the current page.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2348>
---
 js/ui/appDisplay.js | 16 +---------------
 js/ui/iconGrid.js   | 37 +++++++++++++++----------------------
 2 files changed, 16 insertions(+), 37 deletions(-)

diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 5e9ad63fe..5008130ad 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -1172,14 +1172,8 @@ var BaseAppView = GObject.registerClass({
     }
 
     _getDropTarget(x, y, source) {
-        const { currentPage } = this._grid;
-
-        let [item, dragLocation] = this._grid.getDropTarget(x, y);
-
         const [sourcePage, sourcePosition] = this._grid.getItemPosition(source);
-        const targetPage = currentPage;
-        let targetPosition = item
-            ? this._grid.getItemPosition(item)[1] : -1;
+        let [targetPage, targetPosition, dragLocation] = this._grid.getDropTarget(x, y);
 
         // In case we're hovering over the edge of an item but the
         // reflow will happen in the opposite direction (the drag
@@ -1212,14 +1206,6 @@ var BaseAppView = GObject.registerClass({
             }
         }
 
-        // Append to the page if dragging over empty area
-        if (dragLocation === IconGrid.DragLocation.EMPTY_SPACE) {
-            const pageItems =
-                this._grid.getItemsAtPage(currentPage).filter(c => c.visible);
-
-            targetPosition = pageItems.length;
-        }
-
         return [targetPage, targetPosition, dragLocation];
     }
 
diff --git a/js/ui/iconGrid.js b/js/ui/iconGrid.js
index 4e83b56ef..313621a5e 100644
--- a/js/ui/iconGrid.js
+++ b/js/ui/iconGrid.js
@@ -1008,19 +1008,21 @@ var IconGridLayout = GObject.registerClass({
 
         // Out of bounds
         if (page >= this._pages.length)
-            return [null, DragLocation.INVALID];
+            return [0, 0, DragLocation.INVALID];
 
         if (isRtl && this._orientation === Clutter.Orientation.HORIZONTAL)
             page = swap(page, this._pages.length);
 
-        // Page-relative coordinates from now on
+        // Get page-relative coordinates
+        let adjX = x;
+        let adjY = y;
         if (this._orientation === Clutter.Orientation.HORIZONTAL)
-            x %= this._pageWidth;
+            adjX %= this._pageWidth;
         else
-            y %= this._pageHeight;
+            adjY %= this._pageHeight;
 
-        if (x < leftEmptySpace || y < topEmptySpace)
-            return [null, DragLocation.INVALID];
+        if (adjX < leftEmptySpace || adjY < topEmptySpace)
+            return [0, 0, DragLocation.INVALID];
 
         const gridWidth =
             childSize * this.columnsPerPage +
@@ -1029,25 +1031,16 @@ var IconGridLayout = GObject.registerClass({
             childSize * this.rowsPerPage +
             vSpacing * (this.rowsPerPage - 1);
 
-        if (x > leftEmptySpace + gridWidth || y > topEmptySpace + gridHeight)
-            return [null, DragLocation.INVALID];
+        if (adjX > leftEmptySpace + gridWidth || adjY > topEmptySpace + gridHeight)
+            return [0, 0, DragLocation.INVALID];
 
         const halfHSpacing = hSpacing / 2;
         const halfVSpacing = vSpacing / 2;
         const visibleItems = this._pages[page].visibleChildren;
 
-        for (const item of visibleItems) {
-            const childBox = item.allocation.copy();
-
-            // Page offset
-            switch (this._orientation) {
-            case Clutter.Orientation.HORIZONTAL:
-                childBox.set_origin(childBox.x1 % this._pageWidth, childBox.y1);
-                break;
-            case Clutter.Orientation.VERTICAL:
-                childBox.set_origin(childBox.x1, childBox.y1 % this._pageHeight);
-                break;
-            }
+        for (let i = 0; i < visibleItems.length; i++) {
+            const item = visibleItems[i];
+            const childBox = item.allocation;
 
             // Outside the icon boundaries
             if (x < childBox.x1 - halfHSpacing ||
@@ -1072,10 +1065,10 @@ var IconGridLayout = GObject.registerClass({
                     dragLocation = DragLocation.START_EDGE;
             }
 
-            return [item, dragLocation];
+            return [page, i, dragLocation];
         }
 
-        return [null, DragLocation.EMPTY_SPACE];
+        return [page, -1, DragLocation.EMPTY_SPACE];
     }
 
     get iconSize() {