Fix #625: Allow customization of grid card size

ui/dialogs/settingsdialog.go

@@ -519,6 +519,16 @@ func (s *SettingsDialog) createAppearanceTab(window fyne.Window) *container.TabI
 	})
 	disableDPI.Checked = s.config.Application.DisableDPIDetection
 
+	gridCardSize := widget.NewSlider(150, 350)
+	gridCardSize.SetValue(float64(s.config.GridView.CardSize))
+	gridCardSize.Step = 10
+	gridCardSize.OnChanged = func(f float64) {
+		s.config.GridView.CardSize = float32(f)
+		if s.OnPageNeedsRefresh != nil {
+			s.OnPageNeedsRefresh()
+		}
+	}
+
 	return container.NewTabItem(lang.L("Appearance"), container.NewVBox(
 		util.NewHSpace(0), // insert a theme.Padding amount of space at top
 		container.NewBorder(nil, nil, widget.NewLabel(lang.L("Theme")), /*left*/
@@ -527,6 +537,7 @@ func (s *SettingsDialog) createAppearanceTab(window fyne.Window) *container.TabI
 		),
 		widget.NewRichText(&widget.TextSegment{Text: lang.L("UI Scaling"), Style: util.BoldRichTextStyle}),
 		uiScaleRadio,
+		container.NewBorder(nil, nil, widget.NewLabel(lang.L("Grid card size")), nil, gridCardSize),
 		disableDPI,
 		s.newSectionSeparator(),
 		widget.NewRichText(&widget.TextSegment{Text: lang.L("Application font"), Style: util.BoldRichTextStyle}),