Extract TabBar component

src/dusk/ui/tab_bar.cpp

@@ -0,0 +1,122 @@
+#include "tab_bar.hpp"
+
+namespace dusk::ui {
+namespace {
+
+Rml::Element* createRoot(Rml::Element* parent) {
+    auto* doc = parent->GetOwnerDocument();
+    auto elem = doc->CreateElement("div");
+    elem->SetClass("tab-bar", true);
+    return parent->AppendChild(std::move(elem));
+}
+
+}  // namespace
+
+TabBar::TabBar(Rml::Element* parent, Props props)
+    : Component(createRoot(parent)), mProps(std::move(props)) {
+    listen(Rml::EventId::Keydown, [this](Rml::Event& event) {
+        const auto cmd = map_nav_event(event);
+        if (cmd != NavCommand::None && handle_nav_command(event, cmd)) {
+            event.StopPropagation();
+        }
+    });
+}
+
+bool TabBar::focus() {
+    if (mProps.selectedTabIndex >= 0 && mProps.selectedTabIndex < mTabs.size()) {
+        // Try to focus the currently selected tab
+        if (mTabs[mProps.selectedTabIndex].button.focus()) {
+            return true;
+        }
+    }
+    // Otherwise, focus the first enabled tab
+    for (const auto& tab : mTabs) {
+        if (tab.button.focus()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void TabBar::add_tab(const Rml::String& title, TabCallback callback) {
+    const int index = static_cast<int>(mTabs.size());
+    const bool selected = index == mProps.selectedTabIndex;
+    if (selected && callback) {
+        callback();
+    }
+    mTabs.emplace_back(Tab{
+        .title = title,
+        .button = add_child<Button>(mRoot,
+            Button::Props{
+                .text = title,
+                .onPressed = [this, index](Rml::Event&) { set_active_tab(index); },
+                .selected = selected,
+            },
+            "tab"),
+        .callback = std::move(callback),
+    });
+}
+
+bool TabBar::set_active_tab(int index) {
+    if (index < 0 || index >= mTabs.size() || index == mProps.selectedTabIndex) {
+        return false;
+    }
+    const auto& tab = mTabs[index];
+    if (tab.button.focus()) {
+        for (int i = 0; i < static_cast<int>(mTabs.size()); ++i) {
+            mTabs[i].button.set_selected(i == index);
+        }
+        mProps.selectedTabIndex = index;
+        if (tab.callback) {
+            tab.callback();
+        }
+        return true;
+    }
+    return false;
+}
+
+bool TabBar::focus_tab(int index) {
+    if (index < 0 || index >= mTabs.size() || index == mProps.selectedTabIndex) {
+        return false;
+    }
+    const auto& tab = mTabs[index];
+    return tab.button.focus();
+}
+
+int TabBar::tab_containing(Rml::Element* element) const {
+    for (int i = 0; i < mTabs.size(); ++i) {
+        if (mTabs[i].button.contains(element)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+bool TabBar::handle_nav_command(Rml::Event& event, NavCommand cmd) {
+    if (cmd == NavCommand::Left || cmd == NavCommand::Right || cmd == NavCommand::Next ||
+        cmd == NavCommand::Previous)
+    {
+        bool isNext = cmd == NavCommand::Right || cmd == NavCommand::Next;
+        int currentComponent = tab_containing(event.GetTargetElement());
+        int direction = isNext ? 1 : -1;
+        int i = currentComponent + direction;
+        if (currentComponent == -1) {
+            // If the container itself is focused and right is pressed, focus the first element
+            if (isNext) {
+                i = 0;
+            } else {
+                // Otherwise, allow event to bubble
+                return false;
+            }
+        }
+        while (i >= 0 && i < mTabs.size()) {
+            if (mProps.autoSelect ? set_active_tab(i) : focus_tab(i)) {
+                return true;
+            }
+            i += direction;
+        }
+    }
+    return false;
+}
+
+}  // namespace dusk::ui