LibGUI+FontEditor: Move GlyphMapWidget to LibGUI

This will allow us to use this in other apps, such as the upcoming
Character Map. :^)

3 files changed, 363 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/CMakeLists.txt b/Userland/Libraries/LibGUI/CMakeLists.txt
index a0d06444e6..39cdc7c448 100644
--- a/Userland/Libraries/LibGUI/CMakeLists.txt
+++ b/Userland/Libraries/LibGUI/CMakeLists.txt
@@ -42,6 +42,7 @@ set(SOURCES
     FontPicker.cpp
     FontPickerDialogGML.h
     Frame.cpp
+    GlyphMapWidget.cpp
     GMLAutocompleteProvider.cpp
     GMLFormatter.cpp
     GMLLexer.cpp
diff --git a/Userland/Libraries/LibGUI/GlyphMapWidget.cpp b/Userland/Libraries/LibGUI/GlyphMapWidget.cpp
new file mode 100644
index 0000000000..2ac8e91709
--- /dev/null
+++ b/Userland/Libraries/LibGUI/GlyphMapWidget.cpp
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Mustafa Quraish <mustafa@serenityos.org>
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "GlyphMapWidget.h"
+#include <LibGUI/Painter.h>
+#include <LibGfx/BitmapFont.h>
+#include <LibGfx/Emoji.h>
+#include <LibGfx/Palette.h>
+
+namespace GUI {
+
+GlyphMapWidget::Selection GlyphMapWidget::Selection::normalized() const
+{
+    if (m_size > 0)
+        return *this;
+    return { m_start + m_size, -m_size + 1 };
+}
+
+void GlyphMapWidget::Selection::resize_by(int i)
+{
+    m_size += i;
+    if (m_size == 0) {
+        if (i < 0)
+            m_size--;
+        else
+            m_size++;
+    }
+}
+
+bool GlyphMapWidget::Selection::contains(int i) const
+{
+    auto this_normalized = normalized();
+    return i >= this_normalized.m_start && i < this_normalized.m_start + this_normalized.m_size;
+}
+
+void GlyphMapWidget::Selection::extend_to(int glyph)
+{
+    m_size = glyph - m_start;
+    if (m_size > 0)
+        m_size++;
+}
+
+GlyphMapWidget::GlyphMapWidget()
+{
+    set_focus_policy(FocusPolicy::StrongFocus);
+    horizontal_scrollbar().set_visible(false);
+}
+
+GlyphMapWidget::~GlyphMapWidget()
+{
+}
+
+void GlyphMapWidget::initialize(Gfx::BitmapFont& mutable_font)
+{
+    if (m_font == mutable_font)
+        return;
+    m_font = mutable_font;
+    vertical_scrollbar().set_step(font().glyph_height() + m_vertical_spacing);
+    set_active_glyph('A');
+}
+
+void GlyphMapWidget::resize_event(ResizeEvent& event)
+{
+    if (!m_font)
+        return;
+
+    int event_width = event.size().width() - vertical_scrollbar().width() - (frame_thickness() * 2) - m_horizontal_spacing;
+    int event_height = event.size().height() - (frame_thickness() * 2);
+    m_visible_glyphs = (event_width * event_height) / (font().max_glyph_width() * font().glyph_height());
+    m_columns = max(event_width / (font().max_glyph_width() + m_horizontal_spacing), 1);
+    m_rows = ceil_div(m_glyph_count, m_columns);
+
+    int content_width = columns() * (font().max_glyph_width() + m_horizontal_spacing);
+    int content_height = rows() * (font().glyph_height() + m_vertical_spacing) + frame_thickness();
+    set_content_size({ content_width, content_height });
+
+    scroll_to_glyph(m_active_glyph);
+
+    AbstractScrollableWidget::resize_event(event);
+}
+
+void GlyphMapWidget::set_active_glyph(int glyph, ShouldResetSelection should_reset_selection)
+{
+    if (m_active_glyph == glyph)
+        return;
+    m_active_glyph = glyph;
+    if (should_reset_selection == ShouldResetSelection::Yes) {
+        m_selection.set_start(glyph);
+        m_selection.set_size(1);
+    }
+    if (on_active_glyph_changed)
+        on_active_glyph_changed(glyph);
+    update();
+}
+
+Gfx::IntRect GlyphMapWidget::get_outer_rect(int glyph) const
+{
+    int row = glyph / columns();
+    int column = glyph % columns();
+    return Gfx::IntRect {
+        column * (font().max_glyph_width() + m_horizontal_spacing) + 1,
+        row * (font().glyph_height() + m_vertical_spacing) + 1,
+        font().max_glyph_width() + m_horizontal_spacing,
+        font().glyph_height() + m_horizontal_spacing
+    }
+        .translated(frame_thickness() - horizontal_scrollbar().value(), frame_thickness() - vertical_scrollbar().value());
+}
+
+void GlyphMapWidget::update_glyph(int glyph)
+{
+    update(get_outer_rect(glyph));
+}
+
+void GlyphMapWidget::paint_event(PaintEvent& event)
+{
+    Frame::paint_event(event);
+
+    Painter painter(*this);
+    painter.add_clip_rect(widget_inner_rect());
+    painter.add_clip_rect(event.rect());
+
+    painter.set_font(font());
+    painter.fill_rect(widget_inner_rect(), palette().inactive_window_title());
+
+    int scroll_steps = vertical_scrollbar().value() / vertical_scrollbar().step();
+    int first_visible_glyph = scroll_steps * columns();
+
+    for (int glyph = first_visible_glyph; glyph <= first_visible_glyph + m_visible_glyphs && glyph < m_glyph_count; ++glyph) {
+        Gfx::IntRect outer_rect = get_outer_rect(glyph);
+        Gfx::IntRect inner_rect(
+            outer_rect.x() + m_horizontal_spacing / 2,
+            outer_rect.y() + m_vertical_spacing / 2,
+            font().max_glyph_width(),
+            font().glyph_height());
+        if (m_selection.contains(glyph)) {
+            painter.fill_rect(outer_rect, is_focused() ? palette().selection() : palette().inactive_selection());
+            if (m_font->contains_raw_glyph(glyph))
+                painter.draw_glyph(inner_rect.location(), glyph, is_focused() ? palette().selection_text() : palette().inactive_selection_text());
+            else if (auto* emoji = Gfx::Emoji::emoji_for_code_point(glyph))
+                painter.draw_emoji(inner_rect.location(), *emoji, *m_font);
+        } else if (m_font->contains_raw_glyph(glyph)) {
+            painter.fill_rect(outer_rect, palette().base());
+            painter.draw_glyph(inner_rect.location(), glyph, palette().base_text());
+        } else if (auto* emoji = Gfx::Emoji::emoji_for_code_point(glyph)) {
+            painter.fill_rect(outer_rect, Gfx::Color { 255, 150, 150 });
+            painter.draw_emoji(inner_rect.location(), *emoji, *m_font);
+        }
+    }
+    painter.draw_focus_rect(get_outer_rect(m_active_glyph), Gfx::Color::Black);
+}
+
+void GlyphMapWidget::mousedown_event(MouseEvent& event)
+{
+    Frame::mousedown_event(event);
+
+    Gfx::IntPoint map_offset { frame_thickness() - horizontal_scrollbar().value(), frame_thickness() - vertical_scrollbar().value() };
+    auto map_position = event.position() - map_offset;
+    auto col = (map_position.x() - 1) / ((font().max_glyph_width() + m_horizontal_spacing));
+    auto row = (map_position.y() - 1) / ((font().glyph_height() + m_vertical_spacing));
+    auto glyph = row * columns() + col;
+    if (row >= 0 && row < rows() && col >= 0 && col < columns() && glyph < m_glyph_count) {
+        if (event.shift())
+            m_selection.extend_to(glyph);
+        else {
+            m_selection.set_size(1);
+            m_selection.set_start(glyph);
+        }
+        set_active_glyph(glyph, ShouldResetSelection::No);
+    }
+}
+
+void GlyphMapWidget::keydown_event(KeyEvent& event)
+{
+    Frame::keydown_event(event);
+
+    if (!event.ctrl() && !event.shift()) {
+        m_selection.set_size(1);
+        m_selection.set_start(m_active_glyph);
+    }
+
+    if (event.key() == KeyCode::Key_Up) {
+        if (m_selection.start() >= m_columns) {
+            if (event.shift())
+                m_selection.resize_by(-m_columns);
+            else
+                m_selection.set_start(m_selection.start() - m_columns);
+            set_active_glyph(m_active_glyph - m_columns, ShouldResetSelection::No);
+            scroll_to_glyph(m_active_glyph);
+            return;
+        }
+    }
+    if (event.key() == KeyCode::Key_Down) {
+        if (m_selection.start() < m_glyph_count - m_columns) {
+            if (event.shift())
+                m_selection.resize_by(m_columns);
+            else
+                m_selection.set_start(m_selection.start() + m_columns);
+            set_active_glyph(m_active_glyph + m_columns, ShouldResetSelection::No);
+            scroll_to_glyph(m_active_glyph);
+            return;
+        }
+    }
+    if (event.key() == KeyCode::Key_Left) {
+        if (m_selection.start() > 0) {
+            if (event.shift())
+                m_selection.resize_by(-1);
+            else
+                m_selection.set_start(m_selection.start() - 1);
+            set_active_glyph(m_active_glyph - 1, ShouldResetSelection::No);
+            scroll_to_glyph(m_active_glyph);
+            return;
+        }
+    }
+    if (event.key() == KeyCode::Key_Right) {
+        if (m_selection.start() < m_glyph_count - 1) {
+            if (event.shift())
+                m_selection.resize_by(1);
+            else
+                m_selection.set_start(m_selection.start() + 1);
+            set_active_glyph(m_active_glyph + 1, ShouldResetSelection::No);
+            scroll_to_glyph(m_active_glyph);
+            return;
+        }
+    }
+
+    // FIXME: Support selection for these.
+    if (event.ctrl() && event.key() == KeyCode::Key_Home) {
+        set_active_glyph(0);
+        scroll_to_glyph(m_active_glyph);
+        return;
+    }
+    if (event.ctrl() && event.key() == KeyCode::Key_End) {
+        set_active_glyph(m_glyph_count - 1);
+        scroll_to_glyph(m_active_glyph);
+        return;
+    }
+    if (!event.ctrl() && event.key() == KeyCode::Key_Home) {
+        set_active_glyph(m_active_glyph / m_columns * m_columns);
+        return;
+    }
+    if (!event.ctrl() && event.key() == KeyCode::Key_End) {
+        int new_selection = m_active_glyph / m_columns * m_columns + (m_columns - 1);
+        int max = m_glyph_count - 1;
+        new_selection = clamp(new_selection, 0, max);
+        set_active_glyph(new_selection);
+        return;
+    }
+}
+
+void GlyphMapWidget::scroll_to_glyph(int glyph)
+{
+    int row = glyph / columns();
+    int column = glyph % columns();
+    auto scroll_rect = Gfx::IntRect {
+        column * (font().max_glyph_width() + m_horizontal_spacing) + 1,
+        row * (font().glyph_height() + m_vertical_spacing) + 1,
+        font().max_glyph_width() + m_horizontal_spacing,
+        font().glyph_height() + m_horizontal_spacing
+    };
+    scroll_into_view(scroll_rect, true, true);
+}
+
+}
diff --git a/Userland/Libraries/LibGUI/GlyphMapWidget.h b/Userland/Libraries/LibGUI/GlyphMapWidget.h
new file mode 100644
index 0000000000..dbc25e08ec
--- /dev/null
+++ b/Userland/Libraries/LibGUI/GlyphMapWidget.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Vector.h>
+#include <LibGUI/AbstractScrollableWidget.h>
+#include <LibGUI/TextRange.h>
+#include <LibGfx/BitmapFont.h>
+
+namespace GUI {
+
+class GlyphMapWidget final : public AbstractScrollableWidget {
+    C_OBJECT(GlyphMapWidget)
+public:
+    virtual ~GlyphMapWidget() override;
+
+    void initialize(Gfx::BitmapFont&);
+
+    class Selection {
+    public:
+        Selection() = default;
+        Selection(int start, int size)
+            : m_start(start)
+            , m_size(size)
+        {
+        }
+
+        int size() const { return m_size; }
+        void set_size(int i) { m_size = i; }
+        int start() const { return m_start; }
+        void set_start(int i) { m_start = i; }
+
+        Selection normalized() const;
+        bool contains(int) const;
+        void resize_by(int i);
+        void extend_to(int);
+
+    private:
+        int m_start { 0 };
+        int m_size { 1 };
+    };
+
+    Selection selection() const { return m_selection; }
+    int active_glyph() const { return m_active_glyph; }
+
+    enum class ShouldResetSelection {
+        Yes,
+        No
+    };
+
+    void set_active_glyph(int, ShouldResetSelection = ShouldResetSelection::Yes);
+    void clear_selection() { m_selection.set_size(0); }
+    void scroll_to_glyph(int);
+    void update_glyph(int);
+
+    int rows() const { return m_rows; }
+    int columns() const { return m_columns; }
+
+    Gfx::BitmapFont& font() { return *m_font; }
+    Gfx::BitmapFont const& font() const { return *m_font; }
+
+    Function<void(int)> on_active_glyph_changed;
+
+private:
+    GlyphMapWidget();
+    virtual void paint_event(PaintEvent&) override;
+    virtual void mousedown_event(MouseEvent&) override;
+    virtual void keydown_event(KeyEvent&) override;
+    virtual void resize_event(ResizeEvent&) override;
+
+    Gfx::IntRect get_outer_rect(int glyph) const;
+
+    void cut_glyph(int glyph);
+    void copy_glyph(int glyph);
+    void paste_glyph(int glyph);
+    void delete_glyph(int glyph);
+
+    RefPtr<Gfx::BitmapFont> m_font;
+    int m_glyph_count { 0x110000 };
+    int m_columns { 0 };
+    int m_rows { 0 };
+    int m_horizontal_spacing { 2 };
+    int m_vertical_spacing { 2 };
+    Selection m_selection;
+    int m_active_glyph { 0 };
+    int m_visible_glyphs { 0 };
+};
+
+}