GUI: Make thumbnail smaller than its background

This avoids the thumbnail to be drawn over the rounded borders

gui/themes/common/highres_layout.stx

@@ -77,6 +77,8 @@
 		<def var = 'Grid.YSpacing' value = '15' scalable = 'no' resolution = 'x<641' />
 		<def var = 'Grid.ShowTitles' value = '1' scalable = 'no' resolution = 'x<641' />
 
+		<def var = 'Grid.ThumbnailMargin' value = '5' scalable = 'yes' />
+
 		<widget name = 'OptionsLabel'
 				size = '115, Globals.Line.Height'
 				textalign = 'end'

gui/themes/common/lowres_layout.stx

@@ -66,6 +66,8 @@
 		<def var = 'Grid.YSpacing' value = '10' scalable = 'no'/>
 		<def var = 'Grid.ShowTitles' value = '0' scalable = 'no'/>
 
+		<def var = 'Grid.ThumbnailMargin' value = '5' scalable = 'yes' />
+
 		<widget name = 'OptionsLabel'
 				size = '100, Globals.Line.Height'
 				textalign = 'end'

gui/widgets/grid.cpp

@@ -119,7 +119,7 @@ void GridItemWidget::drawWidget() {
 			r.translate(0, kLineHeight);
 		}
 	} else {
-		g_gui.theme()->drawManagedSurface(Common::Point(_x, _y), _thumbGfx);
+		g_gui.theme()->drawManagedSurface(Common::Point(_x + _grid->_thumbnailMargin, _y + _grid->_thumbnailMargin), _thumbGfx);
 	}
 
 	// Draw Platform Icon
@@ -405,6 +405,7 @@ GridWidget::GridWidget(GuiObject *boss, const Common::String &name)
 	_minGridYSpacing = 0;
 	_isTitlesVisible = 0;
 	_scrollBarWidth = 0;
+	_thumbnailMargin = 0;
 
 	_scrollWindowPaddingX = 0;
 	_scrollWindowPaddingY = 0;
@@ -681,6 +682,8 @@ void GridWidget::setGroupHeaderFormat(const Common::U32String &prefix, const Com
 }
 
 void GridWidget::reloadThumbnails() {
+	const int thumbnailWidth = MAX(_thumbnailWidth - 2 * _thumbnailMargin, 0);
+	const int thumbnailHeight = MAX(_thumbnailHeight - 2 * _thumbnailMargin, 0);
 	for (Common::Array<GridItemInfo *>::iterator iter = _visibleEntryList.begin(); iter != _visibleEntryList.end(); ++iter) {
 		GridItemInfo *entry = *iter;
 		if (entry->thumbPath.empty())
@@ -701,7 +704,7 @@ void GridWidget::reloadThumbnails() {
 			}
 
 			if (surf) {
-				const Graphics::ManagedSurface *scSurf(scaleGfx(surf, _thumbnailWidth, _thumbnailHeight, true));
+				const Graphics::ManagedSurface *scSurf(scaleGfx(surf, thumbnailWidth, thumbnailHeight, true));
 				_loadedSurfaces[entry->thumbPath] = scSurf;
 
 				if (path != entry->thumbPath) {
@@ -966,6 +969,11 @@ void GridWidget::reflowLayout() {
 	Widget::reflowLayout();
 	destroyItems();
 
+	// Recompute thumbnail size
+	int oldThumbnailHeight = _thumbnailHeight;
+	int oldThumbnailWidth = _thumbnailWidth;
+	int oldThumbnailMargin = _thumbnailMargin;
+
 	_scrollWindowHeight = _h;
 	_scrollWindowWidth = _w;
 
@@ -975,15 +983,12 @@ void GridWidget::reflowLayout() {
 	_minGridYSpacing = int(g_gui.xmlEval()->getVar("Globals.Grid.YSpacing") * g_gui.getScaleFactor() + .5f);
 	_isTitlesVisible = g_gui.xmlEval()->getVar("Globals.Grid.ShowTitles");
 	_scrollBarWidth = g_gui.xmlEval()->getVar("Globals.Scrollbar.Width", 0);
+	_thumbnailMargin = g_gui.xmlEval()->getVar("Globals.Grid.ThumbnailMargin", 0);
 
 	_scrollWindowPaddingX = _minGridXSpacing;
 	_scrollWindowPaddingY = _minGridYSpacing;
 	_gridYSpacing = _minGridYSpacing;
 
-	// Recompute thumbnail size
-	int oldThumbnailHeight = _thumbnailHeight;
-	int oldThumbnailWidth = _thumbnailWidth;
-
 	int availableWidth = _scrollWindowWidth - (2 * _scrollWindowPaddingX) - _scrollBarWidth;
 	_thumbnailWidth = availableWidth / _itemsPerRow - _minGridXSpacing;
 	const int minimumthumbnailWidth = int(36 * g_gui.getScaleFactor() + .5f);
@@ -999,7 +1004,9 @@ void GridWidget::reflowLayout() {
 	_extraIconWidth = _thumbnailWidth;
 	_extraIconHeight = _thumbnailHeight;
 
-	if ((oldThumbnailHeight != _thumbnailHeight) || (oldThumbnailWidth != _thumbnailWidth)) {
+	if ((oldThumbnailHeight != _thumbnailHeight) ||
+		(oldThumbnailWidth != _thumbnailWidth) ||
+		(oldThumbnailMargin != _thumbnailMargin)) {
 		unloadSurfaces(_extraIcons);
 		unloadSurfaces(_platformIcons);
 		unloadSurfaces(_languageIcons);

gui/widgets/grid.h

@@ -157,6 +157,7 @@ public:
 	int				_gridItemWidth;
 	int				_gridXSpacing;
 	int				_gridYSpacing;
+	int				_thumbnailMargin;
 
 	bool			_isTitlesVisible;