LibGUI: Add a GListView widget.

GListView displays a single column of data from a GModel.

3 files changed, 274 insertions, 0 deletions

diff --git a/LibGUI/GListView.cpp b/LibGUI/GListView.cpp
new file mode 100644
index 0000000000..b3b28a1ce7
--- /dev/null
+++ b/LibGUI/GListView.cpp
@@ -0,0 +1,227 @@
+#include <LibGUI/GListView.h>
+#include <LibGUI/GScrollBar.h>
+#include <LibGUI/GPainter.h>
+#include <Kernel/KeyCode.h>
+
+GListView::GListView(GWidget* parent)
+    : GAbstractView(parent)
+{
+    set_frame_shape(FrameShape::Container);
+    set_frame_shadow(FrameShadow::Sunken);
+    set_frame_thickness(2);
+}
+
+GListView::~GListView()
+{
+}
+
+void GListView::update_content_size()
+{
+    if (!model())
+        return set_content_size({ });
+
+    int content_width = 0;
+    for (int row = 0, row_count = model()->row_count(); row < row_count; ++row) {
+        auto text = model()->data(model()->index(row, m_model_column), GModel::Role::Display);
+        content_width = max(content_width, font().width(text.to_string()));
+    }
+
+    content_width = max(content_width, widget_inner_rect().width());
+
+    int content_height = item_count() * item_height();
+    set_content_size({ content_width, content_height });
+}
+
+void GListView::resize_event(GResizeEvent& event)
+{
+    update_content_size();
+    GAbstractView::resize_event(event);
+}
+
+void GListView::did_update_model()
+{
+    GAbstractView::did_update_model();
+    update_content_size();
+    update();
+}
+
+Rect GListView::content_rect(int row) const
+{
+    return { 0, row * item_height(), content_width(), item_height() };
+}
+
+Rect GListView::content_rect(const GModelIndex& index) const
+{
+    return content_rect(index.row());
+}
+
+Point GListView::adjusted_position(const Point& position)
+{
+    return position.translated(horizontal_scrollbar().value() - frame_thickness(), vertical_scrollbar().value() - frame_thickness());
+}
+
+void GListView::mousedown_event(GMouseEvent& event)
+{
+    if (!model())
+        return;
+
+    if (event.button() != GMouseButton::Left)
+        return;
+
+    auto adjusted_position = this->adjusted_position(event.position());
+    for (int row = 0, row_count = model()->row_count(); row < row_count; ++row) {
+        if (!content_rect(row).contains(adjusted_position))
+            continue;
+        model()->set_selected_index(model()->index(row, m_model_column));
+        update();
+        return;
+    }
+    model()->set_selected_index({ });
+    update();
+}
+
+void GListView::paint_event(GPaintEvent& event)
+{
+    GFrame::paint_event(event);
+
+    if (!model())
+        return;
+
+    GPainter painter(*this);
+    painter.add_clip_rect(frame_inner_rect());
+    painter.add_clip_rect(event.rect());
+    painter.translate(frame_thickness(), frame_thickness());
+    painter.translate(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
+
+    int exposed_width = max(content_size().width(), width());
+    int painted_item_index = 0;
+
+    for (int row_index = 0; row_index < model()->row_count(); ++row_index) {
+        bool is_selected_row = row_index == model()->selected_index().row();
+        int y = painted_item_index * item_height();
+
+        Color background_color;
+        if (is_selected_row) {
+            background_color = is_focused() ? Color::from_rgb(0x84351a) : Color::from_rgb(0x606060);
+        } else {
+            if (alternating_row_colors() && (painted_item_index % 2))
+                background_color = Color(210, 210, 210);
+            else
+                background_color = Color::White;
+        }
+
+        auto column_metadata = model()->column_metadata(m_model_column);
+        const Font& font = column_metadata.font ? *column_metadata.font : this->font();
+        Rect row_rect(0, y, content_width(), item_height());
+        painter.fill_rect(row_rect, background_color);
+        auto index = model()->index(row_index, m_model_column);
+        auto data = model()->data(index);
+        if (data.is_bitmap()) {
+            painter.blit(row_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(row_rect.location(), *bitmap, bitmap->rect());
+        } else {
+            Color text_color;
+            if (is_selected_row)
+                text_color = Color::White;
+            else
+                text_color = model()->data(index, GModel::Role::ForegroundColor).to_color(Color::Black);
+            auto text_rect = row_rect;
+            text_rect.move_by(horizontal_padding(), 0);
+            text_rect.set_width(text_rect.width() - horizontal_padding() * 2);
+            painter.draw_text(text_rect, data.to_string(), font, column_metadata.text_alignment, text_color);
+        }
+
+        ++painted_item_index;
+    };
+
+    Rect unpainted_rect(0, painted_item_index * item_height(), exposed_width, height());
+    painter.fill_rect(unpainted_rect, Color::White);
+}
+
+int GListView::item_count() const
+{
+    if (!model())
+        return 0;
+    return model()->row_count();
+}
+
+void GListView::keydown_event(GKeyEvent& event)
+{
+    if (!model())
+        return;
+    auto& model = *this->model();
+    if (event.key() == KeyCode::Key_Return) {
+        activate(model.selected_index());
+        return;
+    }
+    if (event.key() == KeyCode::Key_Up) {
+        GModelIndex new_index;
+        if (model.selected_index().is_valid())
+            new_index = model.index(model.selected_index().row() - 1, model.selected_index().column());
+        else
+            new_index = model.index(0, 0);
+        if (model.is_valid(new_index)) {
+            model.set_selected_index(new_index);
+            scroll_into_view(new_index, Orientation::Vertical);
+            update();
+        }
+        return;
+    }
+    if (event.key() == KeyCode::Key_Down) {
+        GModelIndex new_index;
+        if (model.selected_index().is_valid())
+            new_index = model.index(model.selected_index().row() + 1, model.selected_index().column());
+        else
+            new_index = model.index(0, 0);
+        if (model.is_valid(new_index)) {
+            model.set_selected_index(new_index);
+            scroll_into_view(new_index, Orientation::Vertical);
+            update();
+        }
+        return;
+    }
+    if (event.key() == KeyCode::Key_PageUp) {
+        int items_per_page = visible_content_rect().height() / item_height();
+        auto new_index = model.index(max(0, model.selected_index().row() - items_per_page), model.selected_index().column());
+        if (model.is_valid(new_index)) {
+            model.set_selected_index(new_index);
+            scroll_into_view(new_index, Orientation::Vertical);
+            update();
+        }
+        return;
+    }
+    if (event.key() == KeyCode::Key_PageDown) {
+        int items_per_page = visible_content_rect().height() / item_height();
+        auto new_index = model.index(min(model.row_count() - 1, model.selected_index().row() + items_per_page), model.selected_index().column());
+        if (model.is_valid(new_index)) {
+            model.set_selected_index(new_index);
+            scroll_into_view(new_index, Orientation::Vertical);
+            update();
+        }
+        return;
+    }
+    return GWidget::keydown_event(event);
+}
+
+void GListView::scroll_into_view(const GModelIndex& index, Orientation orientation)
+{
+    auto rect = content_rect(index.row());
+    GScrollableWidget::scroll_into_view(rect, orientation);
+}
+
+void GListView::doubleclick_event(GMouseEvent& event)
+{
+    if (!model())
+        return;
+    auto& model = *this->model();
+    if (event.button() == GMouseButton::Left) {
+        if (model.selected_index().is_valid()) {
+            if (is_editable())
+                begin_editing(model.selected_index());
+            else
+                activate(model.selected_index());
+        }
+    }
+}
diff --git a/LibGUI/GListView.h b/LibGUI/GListView.h
new file mode 100644
index 0000000000..8cf1c4cb0f
--- /dev/null
+++ b/LibGUI/GListView.h
@@ -0,0 +1,46 @@
+#pragma once
+
+#include <LibGUI/GModel.h>
+#include <LibGUI/GAbstractView.h>
+#include <AK/Function.h>
+#include <AK/HashMap.h>
+
+class GScrollBar;
+class Painter;
+
+class GListView : public GAbstractView {
+public:
+    explicit GListView(GWidget* parent);
+    virtual ~GListView() override;
+
+    int item_height() const { return 16; }
+
+    bool alternating_row_colors() const { return m_alternating_row_colors; }
+    void set_alternating_row_colors(bool b) { m_alternating_row_colors = b; }
+
+    int horizontal_padding() const { return m_horizontal_padding; }
+
+    void scroll_into_view(const GModelIndex&, Orientation);
+
+    Point adjusted_position(const Point&);
+
+    virtual Rect content_rect(const GModelIndex&) const override;
+
+    virtual const char* class_name() const override { return "GListView"; }
+
+private:
+    virtual void did_update_model() override;
+    virtual void paint_event(GPaintEvent&) override;
+    virtual void mousedown_event(GMouseEvent&) override;
+    virtual void doubleclick_event(GMouseEvent&) override;
+    virtual void keydown_event(GKeyEvent&) override;
+    virtual void resize_event(GResizeEvent&) override;
+
+    Rect content_rect(int row) const;
+    int item_count() const;
+    void update_content_size();
+
+    int m_horizontal_padding { 2 };
+    int m_model_column { 0 };
+    bool m_alternating_row_colors { true };
+};
diff --git a/LibGUI/Makefile b/LibGUI/Makefile
index ad9dc3cb28..fc4ce53df1 100644
--- a/LibGUI/Makefile
+++ b/LibGUI/Makefile
@@ -59,6 +59,7 @@ LIBGUI_OBJS = \
     GTabWidget.o \
     GRadioButton.o \
     GAbstractButton.o \
+    GListView.o \
     GWindow.o
 
 OBJS = $(SHAREDGRAPHICS_OBJS) $(LIBGUI_OBJS)