[gnome-shell/gbsneto/cleanup-grid-from-search: 3/4] search: Replace IconGrid from grid search results

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

commit 400d045a6aa1b4703a3fdd5cf5c7e9b54aa60afd
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Mon May 18 13:37:03 2020 -0300

    search: Replace IconGrid from grid search results
    
    Replace the usage of IconGrid in the grid search results by
    a custom layout manager that only allocates as many children
    as the actor can fit.
    
    This new layout manager does not implement changing the icon
    size depending on the screen size.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1265

 .../gnome-shell-sass/widgets/_search-results.scss  |   4 +
 js/ui/search.js                                    | 149 +++++++++++++++++++--
 2 files changed, 139 insertions(+), 14 deletions(-)
---
diff --git a/data/theme/gnome-shell-sass/widgets/_search-results.scss 
b/data/theme/gnome-shell-sass/widgets/_search-results.scss
index 9836724bb3..0d81c974dd 100644
--- a/data/theme/gnome-shell-sass/widgets/_search-results.scss
+++ b/data/theme/gnome-shell-sass/widgets/_search-results.scss
@@ -54,6 +54,10 @@
   @extend %status_text;
 }
 
+.grid-search-results {
+  spacing: $base_spacing * 6;
+}
+
 // Search results with icons
 .grid-search-result {
   @extend %app-well-app;
diff --git a/js/ui/search.js b/js/ui/search.js
index 1c91995380..513f0a1ed2 100644
--- a/js/ui/search.js
+++ b/js/ui/search.js
@@ -13,7 +13,6 @@ const Util = imports.misc.util;
 const SEARCH_PROVIDERS_SCHEMA = 'org.gnome.desktop.search-providers';
 
 var MAX_LIST_SEARCH_RESULTS_ROWS = 5;
-var MAX_GRID_SEARCH_RESULTS_ROWS = 1;
 
 var MaxWidthBox = GObject.registerClass(
 class MaxWidthBox extends St.BoxLayout {
@@ -349,18 +348,140 @@ class ListSearchResults extends SearchResultsBase {
     }
 });
 
+var GridSearchResultsLayout = GObject.registerClass({
+    Properties: {
+        'spacing': GObject.ParamSpec.int('spacing', 'Spacing', 'Spacing',
+            GObject.ParamFlags.READWRITE, 0, GLib.MAXINT32, 0),
+    },
+}, class GridSearchResultsLayout extends Clutter.LayoutManager {
+    _init() {
+        super._init();
+        this._spacing = 0;
+    }
+
+    vfunc_set_container(container) {
+        this._container = container;
+    }
+
+    vfunc_get_preferred_width(container, forHeight) {
+        let minWidth = 0;
+        let natWidth = 0;
+        let first = true;
+
+        for (let child of container) {
+            if (!child.visible)
+                continue;
+
+            const [childMinWidth, childNatWidth] = child.get_preferred_width(forHeight);
+
+            minWidth = Math.max(minWidth, childMinWidth);
+            natWidth += childNatWidth;
+
+            if (first)
+                first = false;
+            else
+                natWidth += this._spacing;
+        }
+
+        return [minWidth, natWidth];
+    }
+
+    vfunc_get_preferred_height(container, forWidth) {
+        let minHeight = 0;
+        let natHeight = 0;
+
+        for (let child of container) {
+            if (!child.visible)
+                continue;
+
+            const [childMinHeight, childNatHeight] = child.get_preferred_height(forWidth);
+
+            minHeight = Math.max(minHeight, childMinHeight);
+            natHeight = Math.max(natHeight, childNatHeight);
+        }
+
+        return [minHeight, natHeight];
+    }
+
+    vfunc_allocate(container, box, flags) {
+        const width = box.get_width();
+
+        const childBox = new Clutter.ActorBox();
+        childBox.x1 = 0;
+        childBox.y1 = 0;
+
+        let first = true;
+        for (let child of container) {
+            if (!child.visible)
+                continue;
+
+            if (first)
+                first = false;
+            else
+                childBox.x1 += this._spacing;
+
+            const [childWidth] = child.get_preferred_width(-1);
+            const [childHeight] = child.get_preferred_height(-1);
+            childBox.set_size(childWidth, childHeight);
+
+            if (childBox.x1 + childWidth > width)
+                return;
+
+            child.allocate(childBox, flags);
+
+            childBox.x1 += childWidth;
+        }
+    }
+
+    columnsForWidth(width) {
+        if (!this._container)
+            return -1;
+
+        const [minWidth] = this.get_preferred_width(this._container, -1);
+
+        if (minWidth === 0)
+            return -1;
+
+        let nCols = 0;
+        while (width > minWidth) {
+            width -= minWidth;
+            if (nCols > 0)
+                width -= this._spacing;
+            nCols++;
+        }
+
+        return nCols;
+    }
+
+    get spacing() {
+        return this._spacing;
+    }
+
+    set spacing(v) {
+        if (this._spacing === v)
+            return;
+        this._spacing = v;
+        this.layout_changed();
+    }
+});
+
 var GridSearchResults = GObject.registerClass(
 class GridSearchResults extends SearchResultsBase {
     _init(provider, resultsView) {
         super._init(provider, resultsView);
 
-        this._grid = new IconGrid.IconGrid({ rowLimit: MAX_GRID_SEARCH_RESULTS_ROWS,
-                                             xAlign: St.Align.START });
+        this._grid = new St.Widget({ style_class: 'grid-search-results' });
+        this._grid.layout_manager = new GridSearchResultsLayout();
 
-        this._bin = new St.Bin({ x_align: Clutter.ActorAlign.CENTER });
-        this._bin.set_child(this._grid);
+        this._grid.connect('style-changed', () => {
+            const node = this._grid.get_theme_node();
+            this._grid.layout_manager.spacing = node.get_length('spacing');
+        });
 
-        this._resultDisplayBin.set_child(this._bin);
+        this._resultDisplayBin.set_child(new St.Bin({
+            child: this._grid,
+            x_align: Clutter.ActorAlign.CENTER,
+        }));
     }
 
     _onDestroy() {
@@ -400,12 +521,11 @@ class GridSearchResults extends SearchResultsBase {
         if (width == 0)
             return -1;
 
-        let nCols = this._grid.columnsForWidth(width);
-        return nCols * this._grid.getRowLimit();
+        return this._grid.layout_manager.columnsForWidth(width);
     }
 
     _clearResultDisplay() {
-        this._grid.removeAll();
+        this._grid.remove_all_children();
     }
 
     _createResultDisplay(meta) {
@@ -414,14 +534,15 @@ class GridSearchResults extends SearchResultsBase {
     }
 
     _addItem(display) {
-        this._grid.addItem(display);
+        this._grid.add_child(display);
     }
 
     getFirstResult() {
-        if (this._grid.visibleItemsCount() > 0)
-            return this._grid.getItemAtIndex(0);
-        else
-            return null;
+        for (let child of this._grid) {
+            if (child.visible)
+                return child;
+        }
+        return null;
     }
 });