LibGUI: Add a MultiView widget, based on FileManager's "DirectoryView"

A MultiView is a combination of ItemView, TableView and ColumnsView
smashed into a single widget. You can switch between the view modes
by calling MultiView::set_view_mode().

Note that MultiView inherits from StackWidget, not AbstractView.
That's purely for practical reasons, although I'm not entirely sure
if there would be some benefit to having it inherit from AbstractView.

4 files changed, 299 insertions, 0 deletions

diff --git a/Libraries/LibGUI/Forward.h b/Libraries/LibGUI/Forward.h
index 3fc85b72e4..ff0c6ba5c1 100644
--- a/Libraries/LibGUI/Forward.h
+++ b/Libraries/LibGUI/Forward.h
@@ -53,6 +53,7 @@ class Model;
 class ModelEditingDelegate;
 class ModelIndex;
 class MouseEvent;
+class MultiView;
 class PaintEvent;
 class Painter;
 class ResizeCorner;
diff --git a/Libraries/LibGUI/Makefile b/Libraries/LibGUI/Makefile
index 3e915fbe7f..dc1bc685b8 100644
--- a/Libraries/LibGUI/Makefile
+++ b/Libraries/LibGUI/Makefile
@@ -40,6 +40,7 @@ OBJS = \
     Model.o \
     ModelIndex.o \
     ModelSelection.o \
+    MultiView.o \
     Notification.o \
     Painter.o \
     ProgressBar.o \
diff --git a/Libraries/LibGUI/MultiView.cpp b/Libraries/LibGUI/MultiView.cpp
new file mode 100644
index 0000000000..162a6c32c4
--- /dev/null
+++ b/Libraries/LibGUI/MultiView.cpp
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/FileSystemPath.h>
+#include <AK/StringBuilder.h>
+#include <LibGUI/Action.h>
+#include <LibGUI/ActionGroup.h>
+#include <LibGUI/Model.h>
+#include <LibGUI/MultiView.h>
+#include <LibGUI/Window.h>
+#include <stdio.h>
+#include <unistd.h>
+
+namespace GUI {
+
+MultiView::MultiView()
+{
+    set_active_widget(nullptr);
+    m_item_view = add<ItemView>();
+    m_columns_view = add<ColumnsView>();
+    m_table_view = add<TableView>();
+
+    m_item_view->on_activation = [&](auto& index) {
+        if (on_activation)
+            on_activation(index);
+    };
+    m_columns_view->on_activation = [&](auto& index) {
+        if (on_activation)
+            on_activation(index);
+    };
+    m_table_view->on_activation = [&](auto& index) {
+        if (on_activation)
+            on_activation(index);
+    };
+
+    m_table_view->on_selection_change = [this] {
+        if (on_selection_change)
+            on_selection_change();
+    };
+    m_item_view->on_selection_change = [this] {
+        if (on_selection_change)
+            on_selection_change();
+    };
+    m_columns_view->on_selection_change = [this] {
+        if (on_selection_change)
+            on_selection_change();
+    };
+
+    m_table_view->on_context_menu_request = [this](auto& index, auto& event) {
+        if (on_context_menu_request)
+            on_context_menu_request(index, event);
+    };
+    m_item_view->on_context_menu_request = [this](auto& index, auto& event) {
+        if (on_context_menu_request)
+            on_context_menu_request(index, event);
+    };
+    m_columns_view->on_context_menu_request = [this](auto& index, auto& event) {
+        if (on_context_menu_request)
+            on_context_menu_request(index, event);
+    };
+
+    m_table_view->on_drop = [this](auto& index, auto& event) {
+        if (on_drop)
+            on_drop(index, event);
+    };
+    m_item_view->on_drop = [this](auto& index, auto& event) {
+        if (on_drop)
+            on_drop(index, event);
+    };
+    m_columns_view->on_drop = [this](auto& index, auto& event) {
+        if (on_drop)
+            on_drop(index, event);
+    };
+
+    set_view_mode(ViewMode::Icon);
+
+    build_actions();
+}
+
+MultiView::~MultiView()
+{
+}
+
+void MultiView::set_view_mode(ViewMode mode)
+{
+    if (m_view_mode == mode)
+        return;
+    m_view_mode = mode;
+    update();
+    if (mode == ViewMode::List) {
+        set_active_widget(m_table_view);
+        return;
+    }
+    if (mode == ViewMode::Columns) {
+        set_active_widget(m_columns_view);
+        return;
+    }
+    if (mode == ViewMode::Icon) {
+        set_active_widget(m_item_view);
+        return;
+    }
+    ASSERT_NOT_REACHED();
+}
+
+void MultiView::set_model(RefPtr<Model> model)
+{
+    if (m_model == model)
+        return;
+    m_model = model;
+    for_each_view_implementation([&](auto& view) {
+        view.set_model(model);
+    });
+}
+
+void MultiView::set_model_column(int column)
+{
+    m_item_view->set_model_column(column);
+    m_columns_view->set_model_column(column);
+}
+
+void MultiView::set_column_hidden(int column_index, bool hidden)
+{
+    m_table_view->set_column_hidden(column_index, hidden);
+}
+
+void MultiView::build_actions()
+{
+    m_view_as_table_action = Action::create(
+        "Table view", Gfx::Bitmap::load_from_file("/res/icons/16x16/table-view.png"), [this](auto&) {
+            set_view_mode(ViewMode::List);
+            m_view_as_table_action->set_checked(true);
+        });
+    m_view_as_table_action->set_checkable(true);
+
+    m_view_as_icons_action = Action::create(
+        "Icon view", Gfx::Bitmap::load_from_file("/res/icons/16x16/icon-view.png"), [this](auto&) {
+            set_view_mode(ViewMode::Icon);
+            m_view_as_icons_action->set_checked(true);
+        });
+    m_view_as_icons_action->set_checkable(true);
+
+    m_view_as_columns_action = Action::create(
+        "Columns view", Gfx::Bitmap::load_from_file("/res/icons/16x16/columns-view.png"), [this](auto&) {
+            set_view_mode(ViewMode::Columns);
+            m_view_as_columns_action->set_checked(true);
+        });
+    m_view_as_columns_action->set_checkable(true);
+
+    m_view_type_action_group = make<ActionGroup>();
+    m_view_type_action_group->set_exclusive(true);
+    m_view_type_action_group->add_action(*m_view_as_table_action);
+    m_view_type_action_group->add_action(*m_view_as_icons_action);
+    m_view_type_action_group->add_action(*m_view_as_columns_action);
+}
+
+}
diff --git a/Libraries/LibGUI/MultiView.h b/Libraries/LibGUI/MultiView.h
new file mode 100644
index 0000000000..19e9a27749
--- /dev/null
+++ b/Libraries/LibGUI/MultiView.h
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibGUI/Action.h>
+#include <LibGUI/ColumnsView.h>
+#include <LibGUI/ItemView.h>
+#include <LibGUI/StackWidget.h>
+#include <LibGUI/TableView.h>
+
+namespace GUI {
+
+class MultiView final : public GUI::StackWidget {
+    C_OBJECT(MultiView)
+public:
+    virtual ~MultiView() override;
+
+    void refresh();
+
+    Function<void()> on_selection_change;
+    Function<void(const ModelIndex&)> on_activation;
+    Function<void(const ModelIndex&)> on_selection;
+    Function<void(const ModelIndex&, const ContextMenuEvent&)> on_context_menu_request;
+    Function<void(const ModelIndex&, const DropEvent&)> on_drop;
+
+    enum ViewMode {
+        List,
+        Columns,
+        Icon
+    };
+    void set_view_mode(ViewMode);
+    ViewMode view_mode() const { return m_view_mode; }
+
+    int model_column() const { return m_model_column; }
+    void set_model_column(int);
+
+    void set_column_hidden(int column_index, bool hidden);
+
+    GUI::AbstractView& current_view()
+    {
+        switch (m_view_mode) {
+        case ViewMode::List:
+            return *m_table_view;
+        case ViewMode::Columns:
+            return *m_columns_view;
+        case ViewMode::Icon:
+            return *m_item_view;
+        default:
+            ASSERT_NOT_REACHED();
+        }
+    }
+
+    const ModelSelection& selection() const { return const_cast<MultiView&>(*this).current_view().selection(); }
+    ModelSelection& selection() { return current_view().selection(); }
+
+    template<typename Callback>
+    void for_each_view_implementation(Callback callback)
+    {
+        callback(*m_table_view);
+        callback(*m_item_view);
+        callback(*m_columns_view);
+    }
+
+    Model* model() { return m_model; }
+    const Model* model() const { return m_model; }
+
+    void set_model(RefPtr<Model>);
+
+    Action& view_as_table_action() { return *m_view_as_table_action; }
+    Action& view_as_icons_action() { return *m_view_as_icons_action; }
+    Action& view_as_columns_action() { return *m_view_as_columns_action; }
+
+private:
+    MultiView();
+
+    void build_actions();
+
+    ViewMode m_view_mode { Icon };
+    int m_model_column { 0 };
+
+    RefPtr<Model> m_model;
+
+    RefPtr<TableView> m_table_view;
+    RefPtr<ItemView> m_item_view;
+    RefPtr<ColumnsView> m_columns_view;
+
+    RefPtr<Action> m_view_as_table_action;
+    RefPtr<Action> m_view_as_icons_action;
+    RefPtr<Action> m_view_as_columns_action;
+
+    OwnPtr<ActionGroup> m_view_type_action_group;
+};
+
+}