GTableView: Add a way to customize cell painting per-column

You can now set a GTableCellPaintingDelegate per column in GTableView.
For columns with a painting delegate set, the view will defer to the
delegate for painting each cell in that column.

2 files changed, 34 insertions, 13 deletions

diff --git a/Libraries/LibGUI/GTableView.cpp b/Libraries/LibGUI/GTableView.cpp
index b7472afd07..9e4e153957 100644
--- a/Libraries/LibGUI/GTableView.cpp
+++ b/Libraries/LibGUI/GTableView.cpp
@@ -158,7 +158,7 @@ void GTableView::mousedown_event(GMouseEvent& event)
                 return;
             }
             auto header_rect = this->header_rect(i);
-	    auto column_metadata = model()->column_metadata(i);
+            auto column_metadata = model()->column_metadata(i);
             if (header_rect.contains(event.position()) && column_metadata.sortable == GModel::ColumnMetadata::Sortable::True) {
                 auto new_sort_order = GSortOrder::Ascending;
                 if (model()->key_column() == i)
@@ -288,19 +288,24 @@ void GTableView::paint_event(GPaintEvent& event)
                 painter.fill_rect(cell_rect_for_fill, key_column_background_color);
             }
             auto cell_index = model()->index(row_index, column_index);
-            auto data = model()->data(cell_index);
-            if (data.is_bitmap()) {
-                painter.blit(cell_rect.location(), data.as_bitmap(), data.as_bitmap().rect());
-            } else if (data.is_icon()) {
-                if (auto bitmap = data.as_icon().bitmap_for_size(16))
-                    painter.blit(cell_rect.location(), *bitmap, bitmap->rect());
+
+            if (auto* delegate = column_data(column_index).cell_painting_delegate.ptr()) {
+                delegate->paint(painter, cell_rect, *model(), cell_index);
             } else {
-                Color text_color;
-                if (is_selected_row)
-                    text_color = Color::White;
-                else
-                    text_color = model()->data(cell_index, GModel::Role::ForegroundColor).to_color(Color::Black);
-                painter.draw_text(cell_rect, data.to_string(), font, column_metadata.text_alignment, text_color, TextElision::Right);
+                auto data = model()->data(cell_index);
+                if (data.is_bitmap()) {
+                    painter.blit(cell_rect.location(), data.as_bitmap(), data.as_bitmap().rect());
+                } else if (data.is_icon()) {
+                    if (auto bitmap = data.as_icon().bitmap_for_size(16))
+                        painter.blit(cell_rect.location(), *bitmap, bitmap->rect());
+                } else {
+                    Color text_color;
+                    if (is_selected_row)
+                        text_color = Color::White;
+                    else
+                        text_color = model()->data(cell_index, GModel::Role::ForegroundColor).to_color(Color::Black);
+                    painter.draw_text(cell_rect, data.to_string(), font, column_metadata.text_alignment, text_color, TextElision::Right);
+                }
             }
             x_offset += column_width + horizontal_padding() * 2;
         }
@@ -512,3 +517,8 @@ const Font& GTableView::header_font()
 {
     return Font::default_bold_font();
 }
+
+void GTableView::set_cell_painting_delegate(int column, OwnPtr<GTableCellPaintingDelegate>&& delegate)
+{
+    column_data(column).cell_painting_delegate = move(delegate);
+}
diff --git a/Libraries/LibGUI/GTableView.h b/Libraries/LibGUI/GTableView.h
index 1935bab13e..a469740cf1 100644
--- a/Libraries/LibGUI/GTableView.h
+++ b/Libraries/LibGUI/GTableView.h
@@ -5,9 +5,17 @@
 #include <LibGUI/GAbstractView.h>
 #include <LibGUI/GModel.h>
 
+class GPainter;
 class GScrollBar;
 class Painter;
 
+class GTableCellPaintingDelegate {
+public:
+    virtual ~GTableCellPaintingDelegate() {}
+
+    virtual void paint(GPainter&, const Rect&, const GModel&, const GModelIndex&) = 0;
+};
+
 class GTableView : public GAbstractView {
     C_OBJECT(GTableView)
 public:
@@ -38,6 +46,8 @@ public:
 
     virtual Rect content_rect(const GModelIndex&) const override;
 
+    void set_cell_painting_delegate(int column, OwnPtr<GTableCellPaintingDelegate>&&);
+
 private:
     virtual void did_update_model() override;
     virtual void paint_event(GPaintEvent&) override;
@@ -67,6 +77,7 @@ private:
         bool has_initialized_width { false };
         bool visibility { true };
         RefPtr<GAction> visibility_action;
+        OwnPtr<GTableCellPaintingDelegate> cell_painting_delegate;
     };
     ColumnData& column_data(int column) const;