New Widget: TabHeader

A new tab header that sites above (bellow?) the tab view. Basic draing,
no interaction, all tabs have the same size, no close button.

CMakeLists.txt

@@ -95,6 +95,8 @@ set(SVISION_SOURCES
     src/spinbox.h
     src/stackwidget.cpp
     src/stackwidget.h
+    src/tabheader.cpp
+    src/tabheader.h
     src/theme.cpp
     src/theme.h
     src/timer.cpp

src/tabheader.cpp

@@ -0,0 +1,73 @@
+/*
+ * This file is part of SVision2
+ * Copyright (c) Diego Iastrubni <[email protected]>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "tabheader.h"
+#include "theme.h"
+
+TabHeader::TabHeader() : Widget() {
+    //
+}
+
+auto TabHeader::add_tab(const std::string_view name) -> int {
+    this->names.push_back(name);
+    return this->names.size() - 1;
+}
+
+auto TabHeader::remove_tab(int index) -> void { this->names.erase(this->names.begin() + index); }
+
+auto TabHeader::set_active_tab(int index) -> void {
+    this->active_tab = index;
+    this->invalidate();
+}
+
+auto TabHeader::get_tab_string(int index) const -> std::string_view {
+    if (index < 0 || index >= names.size()) {
+        return "";
+    }
+    return this->names[index];
+}
+
+auto default_padding_y = 5;
+auto default_padding_x = 20;
+
+auto TabHeader::draw() -> void {
+    auto theme = get_theme();
+    auto offset = 0;
+    auto &font = theme->font;
+
+    auto active_bg = theme->colors.button_background_2;
+    auto non_active_bg = Darker(theme->colors.button_background_1);
+
+    theme->draw_widget_background(content, has_focus);
+
+    this->content.fill(0);
+    auto i = 0;
+    for (auto s : names) {
+        auto is_active_tab = i == this->active_tab;
+        auto padding_x = default_padding_x;
+        auto padding_y = 5;
+
+        auto tab_size = font.text_size(s);
+        auto bg_color = i == active_tab ? active_bg : non_active_bg;
+        auto position_y = is_active_tab ? 0 : padding_y;
+
+        this->content.fill_rect(offset, position_y, tab_size.width + padding_x * 2,
+                                tab_size.height + padding_y * 2, bg_color);
+
+        font.write(this->content, {offset + padding_x, padding_y}, s, 0x00);
+        offset += tab_size.width;
+        offset += padding_x + padding_x;
+        i++;
+    }
+}
+
+auto TabHeader::size_hint() const -> Size {
+    auto hint = this->get_theme()->font.text_size("X");
+    hint.width = 0;
+    hint.height += default_padding_y * 2;
+    return hint;
+}

src/tabheader.h

@@ -0,0 +1,28 @@
+/*
+ * This file is part of SVision2
+ * Copyright (c) Diego Iastrubni <[email protected]>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <widget.h>
+
+struct TabHeader : Widget {
+    std::vector<std::string_view> names;
+
+    TabHeader();
+
+    auto add_tab(const std::string_view name) -> int;
+    auto remove_tab(int index) -> void;
+    auto get_tab_string(int index) const -> std::string_view;
+    auto set_active_tab(int index) -> void;
+    auto get_active_tab() const -> int { return active_tab; }
+
+    virtual auto draw() -> void override;
+    virtual auto size_hint() const -> Size override;
+
+  private:
+    int active_tab = 0;
+};