GFilePicker: Add a button for moving up to parent directory.

LibGUI/GFilePicker.cpp

@@ -5,6 +5,8 @@
 #include <LibGUI/GLabel.h>
 #include <LibGUI/GButton.h>
 #include <LibGUI/GSortingProxyModel.h>
+#include <LibGUI/GAction.h>
+#include <LibGUI/GToolBar.h>
 #include <AK/FileSystemPath.h>
 
 GFilePicker::GFilePicker(const String& path, CObject* parent)
@@ -19,10 +21,22 @@ GFilePicker::GFilePicker(const String& path, CObject* parent)
     main_widget()->layout()->set_spacing(4);
     main_widget()->set_fill_with_background_color(true);
     main_widget()->set_background_color(Color::LightGray);
-    m_view = new GTableView(main_widget());
+
+    auto* upper_container = new GWidget(main_widget());
+    upper_container->set_layout(make<GBoxLayout>(Orientation::Vertical));
+    upper_container->layout()->set_spacing(4);
+
+    auto* toolbar = new GToolBar(upper_container);
+
+    m_view = new GTableView(upper_container);
     m_view->set_model(GSortingProxyModel::create(*m_model));
     m_model->open(path);
 
+    auto open_parent_directory_action = GAction::create("Open parent directory", { Mod_Alt, Key_Up }, GraphicsBitmap::load_from_file("/res/icons/16x16/open-parent-directory.png"), [this] (const GAction&) {
+        m_model->open(String::format("%s/..", m_model->path().characters()));
+    });
+    toolbar->add_action(*open_parent_directory_action);
+
     auto* lower_container = new GWidget(main_widget());
     lower_container->set_layout(make<GBoxLayout>(Orientation::Vertical));
     lower_container->layout()->set_spacing(4);
@@ -39,16 +53,19 @@ GFilePicker::GFilePicker(const String& path, CObject* parent)
     filename_label->set_preferred_size({ 60, 0 });
     auto* filename_textbox = new GTextBox(filename_container);
 
-    m_view->on_activation = [&] (auto& index) {
+    m_view->on_activation = [this, filename_textbox] (auto& index) {
         auto& filter_model = (GSortingProxyModel&)*m_view->model();
         auto local_index = filter_model.map_to_target(index);
         const GDirectoryModel::Entry& entry = m_model->entry(local_index.row());
 
         FileSystemPath path(String::format("%s/%s", m_model->path().characters(), entry.name.characters()));
 
-        if (entry.is_directory())
+        if (entry.is_directory()) {
             m_model->open(path.string());
-        filename_textbox->set_text(entry.name);
+            // NOTE: 'entry' is invalid from here on
+        } else {
+            filename_textbox->set_text(entry.name);
+        }
     };
 
     auto* button_container = new GWidget(lower_container);

LibGUI/GSortingProxyModel.cpp

@@ -78,8 +78,10 @@ void GSortingProxyModel::resort()
     m_row_mappings.resize(row_count);
     for (int i = 0; i < row_count; ++i)
         m_row_mappings[i] = i;
-    if (m_key_column == -1)
+    if (m_key_column == -1) {
+        did_update();
         return;
+    }
     quick_sort(m_row_mappings.begin(), m_row_mappings.end(), [&] (auto row1, auto row2) -> bool {
         auto data1 = target().data(target().index(row1, m_key_column), GModel::Role::Sort);
         auto data2 = target().data(target().index(row2, m_key_column), GModel::Role::Sort);
@@ -90,6 +92,7 @@ void GSortingProxyModel::resort()
     });
     if (previously_selected_target_row != -1) {
         // Preserve selection.
+        ASSERT(m_row_mappings.size() == row_count);
         for (int i = 0; i < row_count; ++i) {
             if (m_row_mappings[i] == previously_selected_target_row) {
                 set_selected_index(index(i, 0));