[gnome-shell] iconGrid: Add minRows/minColumns properties

[Carlos Soriano <csoriano src gnome org>]

commit ae263bb4db3d3fd7edef9c1fde8866655e2a0a85
Author: Carlos Soriano <carlos soriano89 gmail com>
Date:   Tue Aug 27 21:23:13 2013 +0200

    iconGrid: Add minRows/minColumns properties
    
    When we adapt the grid to different display sizes,
    we don't want the number of displayed items to get
    too small. In the future we will scale down icons to
    make sure that the grid fits add least minRows
    x minColumns items, but for now we only take the
    properties into account when calculating the dynamic spacing.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=706081

 js/ui/appDisplay.js |    4 ++++
 js/ui/iconGrid.js   |   36 +++++++++++++++++++++++++-----------
 2 files changed, 29 insertions(+), 11 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 30d033c..0dd3885 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -30,6 +30,8 @@ const Util = imports.misc.util;
 const MAX_APPLICATION_WORK_MILLIS = 75;
 const MENU_POPUP_TIMEOUT = 600;
 const MAX_COLUMNS = 6;
+const MIN_COLUMNS = 4;
+const MIN_ROWS = 4;
 
 const INACTIVE_GRID_OPACITY = 77;
 const INACTIVE_GRID_OPACITY_ANIMATION_TIME = 0.15;
@@ -63,6 +65,8 @@ const BaseAppView = new Lang.Class({
     _init: function(params, gridParams) {
         gridParams = Params.parse(gridParams, { xAlign: St.Align.MIDDLE,
                                                 columnLimit: MAX_COLUMNS,
+                                                minRows: MIN_ROWS,
+                                                minColumns: MIN_COLUMNS,
                                                 fillParent: false });
         params = Params.parse(params, { usePagination: false });
 
diff --git a/js/ui/iconGrid.js b/js/ui/iconGrid.js
index 59c6360..fa04bf8 100644
--- a/js/ui/iconGrid.js
+++ b/js/ui/iconGrid.js
@@ -176,10 +176,14 @@ const IconGrid = new Lang.Class({
     _init: function(params) {
         params = Params.parse(params, { rowLimit: null,
                                         columnLimit: null,
+                                        minRows: 1,
+                                        minColumns: 1,
                                         fillParent: false,
                                         xAlign: St.Align.MIDDLE });
         this._rowLimit = params.rowLimit;
         this._colLimit = params.columnLimit;
+        this._minRows = params.minRows;
+        this._minColumns = params.minColumns;
         this._xAlign = params.xAlign;
         this._fillParent = params.fillParent;
 
@@ -393,17 +397,27 @@ const IconGrid = new Lang.Class({
      * This function must to be called before iconGrid allocation,
      * to know how much spacing can the grid has
      */
-    updateSpacingForSize: function(availWidth) {
-        let spacing = this._spacing;
-
-        if (this._colLimit) {
-            let itemWidth = this._hItemSize * this._colLimit;
-            let emptyArea = availWidth - itemWidth;
-            spacing = Math.max(spacing, emptyArea / (2 * this._colLimit));
-            spacing = Math.round(spacing);
-        }
-        this.setSpacing(spacing);
-    },
+    updateSpacingForSize: function(availWidth, availHeight) {
+        let maxEmptyVArea = availHeight - this._minRows * this._vItemSize;
+        let maxEmptyHArea = availWidth - this._minColumns * this._hItemSize;
+        let maxHSpacing, maxVSpacing;
+        if (this._minRows <= 1)
+            maxVSpacing = maxEmptyVArea;
+        else
+            maxVSpacing = Math.floor(maxEmptyVArea / (this._minRows - 1));
+
+        if (this._minColumns <= 1)
+            maxHSpacing = maxEmptyHArea;
+        else
+            maxHSpacing = Math.floor(maxEmptyHArea / (this._minColumns - 1));
+
+        let maxSpacing = Math.min(maxHSpacing, maxVSpacing);
+        // Limit spacing to the item size
+        maxSpacing = Math.min(maxSpacing, Math.min(this._vItemSize, this._hItemSize));
+        // The minimum spacing, regardless of whether it satisfies the row/column minima,
+        // is the spacing we get from CSS.
+        this.setSpacing(Math.max(this._spacing, maxSpacing));
+    }
 });
 
 const PaginatedIconGrid = new Lang.Class({