LibGUI+HackStudio: Add an opt-in autocompletion interface to TextEditor

...and use that to implement autocomplete in HackStudio.

Now everyone can have autocomplete :^)

Libraries/LibGUI/AutocompleteProvider.cpp

@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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 <LibGUI/AutocompleteProvider.h>
+#include <LibGUI/Model.h>
+#include <LibGUI/TableView.h>
+#include <LibGUI/TextEditor.h>
+#include <LibGUI/Window.h>
+#include <LibGfx/Bitmap.h>
+
+static RefPtr<Gfx::Bitmap> s_cpp_identifier_icon;
+static RefPtr<Gfx::Bitmap> s_unspecified_identifier_icon;
+
+namespace GUI {
+
+class AutocompleteSuggestionModel final : public GUI::Model {
+public:
+    explicit AutocompleteSuggestionModel(Vector<AutocompleteProvider::Entry>&& suggestions)
+        : m_suggestions(move(suggestions))
+    {
+    }
+
+    enum Column {
+        Icon,
+        Name,
+        __Column_Count,
+    };
+
+    enum InternalRole {
+        __ModelRoleCustom = (int)GUI::ModelRole::Custom,
+        PartialInputLength,
+        Kind,
+    };
+
+    virtual int row_count(const GUI::ModelIndex& = GUI::ModelIndex()) const override { return m_suggestions.size(); }
+    virtual int column_count(const GUI::ModelIndex& = GUI::ModelIndex()) const override { return Column::__Column_Count; }
+    virtual GUI::Variant data(const GUI::ModelIndex& index, GUI::ModelRole role) const override
+    {
+        auto& suggestion = m_suggestions.at(index.row());
+        if (role == GUI::ModelRole::Display) {
+            if (index.column() == Column::Name) {
+                return suggestion.completion;
+            }
+            if (index.column() == Column::Icon) {
+                // TODO
+                if (suggestion.language == GUI::AutocompleteProvider::Language::Cpp) {
+                    if (!s_cpp_identifier_icon) {
+                        s_cpp_identifier_icon = Gfx::Bitmap::load_from_file("/res/icons/16x16/completion/cpp-identifier.png");
+                    }
+                    return *s_cpp_identifier_icon;
+                }
+                if (suggestion.language == GUI::AutocompleteProvider::Language::Unspecified) {
+                    if (!s_unspecified_identifier_icon) {
+                        s_unspecified_identifier_icon = Gfx::Bitmap::load_from_file("/res/icons/16x16/completion/unspecified-identifier.png");
+                    }
+                    return *s_unspecified_identifier_icon;
+                }
+                return {};
+            }
+        }
+
+        if ((int)role == InternalRole::Kind)
+            return (u32)suggestion.kind;
+
+        if ((int)role == InternalRole::PartialInputLength)
+            return (i64)suggestion.partial_input_length;
+
+        return {};
+    }
+    virtual void update() override {};
+
+private:
+    Vector<AutocompleteProvider::Entry> m_suggestions;
+};
+
+AutocompleteBox::~AutocompleteBox() { }
+
+AutocompleteBox::AutocompleteBox(TextEditor& editor)
+    : m_editor(editor)
+{
+    m_popup_window = GUI::Window::construct();
+    m_popup_window->set_window_type(GUI::WindowType::Tooltip);
+    m_popup_window->set_rect(0, 0, 200, 100);
+
+    m_suggestion_view = m_popup_window->set_main_widget<GUI::TableView>();
+    m_suggestion_view->set_column_headers_visible(false);
+}
+
+void AutocompleteBox::update_suggestions(Vector<AutocompleteProvider::Entry>&& suggestions)
+{
+    if (suggestions.is_empty())
+        return;
+
+    bool has_suggestions = !suggestions.is_empty();
+    m_suggestion_view->set_model(adopt(*new AutocompleteSuggestionModel(move(suggestions))));
+
+    if (!has_suggestions)
+        m_suggestion_view->selection().clear();
+    else
+        m_suggestion_view->selection().set(m_suggestion_view->model()->index(0));
+}
+
+bool AutocompleteBox::is_visible() const
+{
+    return m_popup_window->is_visible();
+}
+
+void AutocompleteBox::show(Gfx::IntPoint suggstion_box_location)
+{
+    m_popup_window->move_to(suggstion_box_location);
+    m_popup_window->show();
+}
+
+void AutocompleteBox::close()
+{
+    m_popup_window->hide();
+}
+
+void AutocompleteBox::next_suggestion()
+{
+    GUI::ModelIndex new_index = m_suggestion_view->selection().first();
+    if (new_index.is_valid())
+        new_index = m_suggestion_view->model()->index(new_index.row() + 1);
+    else
+        new_index = m_suggestion_view->model()->index(0);
+
+    if (m_suggestion_view->model()->is_valid(new_index)) {
+        m_suggestion_view->selection().set(new_index);
+        m_suggestion_view->scroll_into_view(new_index, Orientation::Vertical);
+    }
+}
+
+void AutocompleteBox::previous_suggestion()
+{
+    GUI::ModelIndex new_index = m_suggestion_view->selection().first();
+    if (new_index.is_valid())
+        new_index = m_suggestion_view->model()->index(new_index.row() - 1);
+    else
+        new_index = m_suggestion_view->model()->index(0);
+
+    if (m_suggestion_view->model()->is_valid(new_index)) {
+        m_suggestion_view->selection().set(new_index);
+        m_suggestion_view->scroll_into_view(new_index, Orientation::Vertical);
+    }
+}
+
+void AutocompleteBox::apply_suggestion()
+{
+    if (m_editor.is_null())
+        return;
+
+    if (!m_editor->is_editable())
+        return;
+
+    auto selected_index = m_suggestion_view->selection().first();
+    if (!selected_index.is_valid())
+        return;
+
+    auto suggestion_index = m_suggestion_view->model()->index(selected_index.row(), AutocompleteSuggestionModel::Column::Name);
+    auto suggestion = suggestion_index.data().to_string();
+    size_t partial_length = suggestion_index.data((GUI::ModelRole)AutocompleteSuggestionModel::InternalRole::PartialInputLength).to_i64();
+
+    ASSERT(suggestion.length() >= partial_length);
+    auto completion = suggestion.substring_view(partial_length, suggestion.length() - partial_length);
+    m_editor->insert_at_cursor_or_replace_selection(completion);
+}
+
+}

Libraries/LibGUI/AutocompleteProvider.h

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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/Forward.h>
+#include <LibGUI/TextEditor.h>
+#include <LibGUI/Window.h>
+
+namespace GUI {
+
+class AutocompleteProvider {
+    AK_MAKE_NONCOPYABLE(AutocompleteProvider);
+    AK_MAKE_NONMOVABLE(AutocompleteProvider);
+
+public:
+    virtual ~AutocompleteProvider() { }
+
+    enum class CompletionKind {
+        Identifier,
+    };
+
+    enum class Language {
+        Unspecified,
+        Cpp,
+    };
+
+    struct Entry {
+        String completion;
+        size_t partial_input_length { 0 };
+        CompletionKind kind { CompletionKind::Identifier };
+        Language language { Language::Unspecified };
+    };
+
+    virtual void provide_completions(Function<void(Vector<Entry>)>) = 0;
+
+    void attach(TextEditor& editor)
+    {
+        ASSERT(!m_editor);
+        m_editor = editor;
+    }
+    void detach() { m_editor.clear(); }
+
+protected:
+    AutocompleteProvider() { }
+
+    WeakPtr<TextEditor> m_editor;
+};
+
+class AutocompleteBox final {
+public:
+    explicit AutocompleteBox(TextEditor&);
+    ~AutocompleteBox();
+
+    void update_suggestions(Vector<AutocompleteProvider::Entry>&& suggestions);
+    bool is_visible() const;
+    void show(Gfx::IntPoint suggstion_box_location);
+    void close();
+
+    void next_suggestion();
+    void previous_suggestion();
+    void apply_suggestion();
+
+private:
+    WeakPtr<TextEditor> m_editor;
+    RefPtr<GUI::Window> m_popup_window;
+    RefPtr<GUI::TableView> m_suggestion_view;
+};
+
+}

Libraries/LibGUI/CMakeLists.txt

@@ -6,9 +6,10 @@ set(SOURCES
     Action.cpp
     ActionGroup.cpp
     Application.cpp
+    AutocompleteProvider.cpp
     BoxLayout.cpp
-    Button.cpp
     BreadcrumbBar.cpp
+    Button.cpp
     Calendar.cpp
     CheckBox.cpp
     Clipboard.cpp

Libraries/LibGUI/TextEditor.cpp

@@ -25,10 +25,12 @@
  */
 
 #include <AK/QuickSort.h>
+#include <AK/ScopeGuard.h>
 #include <AK/StringBuilder.h>
 #include <AK/TemporaryChange.h>
 #include <LibCore/Timer.h>
 #include <LibGUI/Action.h>
+#include <LibGUI/AutocompleteProvider.h>
 #include <LibGUI/Clipboard.h>
 #include <LibGUI/InputBox.h>
 #include <LibGUI/Menu.h>
@@ -711,6 +713,27 @@ void TextEditor::sort_selected_lines()
 
 void TextEditor::keydown_event(KeyEvent& event)
 {
+    if (m_autocomplete_box && m_autocomplete_box->is_visible() && (event.key() == KeyCode::Key_Return || event.key() == KeyCode::Key_Tab)) {
+        m_autocomplete_box->apply_suggestion();
+        m_autocomplete_box->close();
+        return;
+    }
+
+    if (m_autocomplete_box && m_autocomplete_box->is_visible() && event.key() == KeyCode::Key_Escape) {
+        m_autocomplete_box->close();
+        return;
+    }
+
+    if (m_autocomplete_box && m_autocomplete_box->is_visible() && event.key() == KeyCode::Key_Up) {
+        m_autocomplete_box->previous_suggestion();
+        return;
+    }
+
+    if (m_autocomplete_box && m_autocomplete_box->is_visible() && event.key() == KeyCode::Key_Down) {
+        m_autocomplete_box->next_suggestion();
+        return;
+    }
+
     if (is_single_line() && event.key() == KeyCode::Key_Tab)
         return ScrollableWidget::keydown_event(event);
 
@@ -720,6 +743,14 @@ void TextEditor::keydown_event(KeyEvent& event)
         return;
     }
 
+    ArmedScopeGuard update_autocomplete { [&] {
+        if (m_autocomplete_box && m_autocomplete_box->is_visible()) {
+            m_autocomplete_provider->provide_completions([&](auto completions) {
+                m_autocomplete_box->update_suggestions(move(completions));
+            });
+        }
+    } };
+
     if (event.key() == KeyCode::Key_Escape) {
         if (on_escape_pressed)
             on_escape_pressed();
@@ -997,6 +1028,18 @@ void TextEditor::keydown_event(KeyEvent& event)
         return;
     }
 
+    if (!event.shift() && !event.alt() && event.ctrl() && event.key() == KeyCode::Key_Space) {
+        if (m_autocomplete_provider) {
+            m_autocomplete_provider->provide_completions([&](auto completions) {
+                m_autocomplete_box->update_suggestions(move(completions));
+                auto position = content_rect_for_position(cursor()).bottom_right().translated(screen_relative_rect().top_left().translated(ruler_width(), 0).translated(10, 5));
+                m_autocomplete_box->show(position);
+            });
+            update_autocomplete.disarm();
+            return;
+        }
+    }
+
     if (is_editable() && !event.ctrl() && !event.alt() && event.code_point() != 0) {
         StringBuilder sb;
         sb.append_code_point(event.code_point());
@@ -1759,6 +1802,25 @@ void TextEditor::set_syntax_highlighter(OwnPtr<SyntaxHighlighter> highlighter)
         document().set_spans({});
 }
 
+const AutocompleteProvider* TextEditor::autocomplete_provider() const
+{
+    return m_autocomplete_provider.ptr();
+}
+
+void TextEditor::set_autocomplete_provider(OwnPtr<AutocompleteProvider>&& provider)
+{
+    if (m_autocomplete_provider)
+        m_autocomplete_provider->detach();
+    m_autocomplete_provider = move(provider);
+    if (m_autocomplete_provider) {
+        m_autocomplete_provider->attach(*this);
+        if (!m_autocomplete_box)
+            m_autocomplete_box = make<AutocompleteBox>(*this);
+    }
+    if (m_autocomplete_box)
+        m_autocomplete_box->close();
+}
+
 int TextEditor::line_height() const
 {
     return font().glyph_height() + m_line_spacing;

Libraries/LibGUI/TextEditor.h

@@ -30,6 +30,7 @@
 #include <AK/NonnullOwnPtrVector.h>
 #include <AK/NonnullRefPtrVector.h>
 #include <LibCore/ElapsedTimer.h>
+#include <LibGUI/Forward.h>
 #include <LibGUI/ScrollableWidget.h>
 #include <LibGUI/TextDocument.h>
 #include <LibGUI/TextRange.h>
@@ -159,6 +160,9 @@ public:
     const SyntaxHighlighter* syntax_highlighter() const;
     void set_syntax_highlighter(OwnPtr<SyntaxHighlighter>);
 
+    const AutocompleteProvider* autocomplete_provider() const;
+    void set_autocomplete_provider(OwnPtr<AutocompleteProvider>&&);
+
     bool is_in_drag_select() const { return m_in_drag_select; }
 
 protected:
@@ -317,6 +321,8 @@ private:
     NonnullOwnPtrVector<LineVisualData> m_line_visual_data;
 
     OwnPtr<SyntaxHighlighter> m_highlighter;
+    OwnPtr<AutocompleteProvider> m_autocomplete_provider;
+    OwnPtr<AutocompleteBox> m_autocomplete_box;
 
     RefPtr<Core::Timer> m_automatic_selection_scroll_timer;
     Gfx::IntPoint m_last_mousemove_position;