Add ImGui tab bar to Lua

examples/window.lua

@@ -15,6 +15,9 @@ local inputcolorrgba = Color:new(0.0, 0.0, 1.0, 0.5) -- 50% opacity blue
 
 local inputtooltip = 'This input\'s value is used as its tooltip.'
 
+local extratabs = {}
+local nextextratabid = 1
+
 local widgetopen = true
 local closebutton = false
 
@@ -125,6 +128,39 @@ set_callback(function(draw_ctx)
                 draw_ctx:win_imagebutton('##coolbutton', loadingimage, 0.33, 0.11, 0, 0, 1, 1)
             end
 
+            draw_ctx:win_separator_text('Tabs')
+
+            draw_ctx:win_tab_bar('ExampleTabBar', function()
+                draw_ctx:win_tab_item('Small Tab', false, function()
+                    draw_ctx:win_text('Not much to see here.')
+                end)
+                draw_ctx:win_tab_item('Large Tab', false, function()
+                    draw_ctx:win_text('This tab has a lot of content.')
+                    for i=1,20 do
+                        draw_ctx:win_text('Content #'..i)
+                        draw_ctx:win_inline()
+                        draw_ctx:win_button('Button #'..i)
+                    end
+                end)
+                local i = 1
+                while i <= #extratabs do
+                    local open = draw_ctx:win_tab_item(extratabs[i], true, function()
+                        draw_ctx:win_text('This is '..extratabs[i]..'. It can be closed with the X.')
+                    end)
+                    if open then
+                        i = i + 1
+                    else
+                        table.remove(extratabs, i)
+                    end
+                end
+                if draw_ctx:win_tab_item_button('+') then
+                    table.insert(extratabs, 'Extra Tab #'..nextextratabid)
+                    nextextratabid = nextextratabid + 1
+                end
+            end)
+
+            draw_ctx:win_separator_text('Identical Input Labels')
+
             -- remember to use unique labels on identical inputs
             if draw_ctx:win_button('Test##FirstTest') then
                 message('First button')
@@ -150,7 +186,7 @@ set_callback(function(draw_ctx)
             end
 
             -- or with pushid (string)
-            local b_ids = { "first", "second", "third" }
+            local b_ids = { 'first', 'second', 'third' }
             b = {}
             for i, id in ipairs(b_ids) do
                 draw_ctx:win_pushid(id)

src/game_api/script/usertypes/gui_lua.cpp

@@ -550,6 +550,31 @@ void GuiDrawContext::win_section(std::string title, sol::function callback)
     if (ImGui::CollapsingHeader(title.c_str()))
         handle_function<void>(backend, callback);
 };
+void GuiDrawContext::win_tab_bar(std::string id, sol::function callback)
+{
+    // TODO: Which ImGuiTabBarFlags should be exposed? ImGuiTabBarFlags_Reorderable and ImGuiTabBarFlags_AutoSelectNewTabs seem useful.
+    if (ImGui::BeginTabBar(id.c_str()))
+    {
+        handle_function<void>(backend, callback);
+        ImGui::EndTabBar();
+    }
+};
+bool GuiDrawContext::win_tab_item(std::string label, bool closeable, sol::function callback)
+{
+    // TODO: Which ImGuiTabItemFlags should be exposed? Many of them seem useful.
+    bool open = true;
+    if (ImGui::BeginTabItem(label.c_str(), closeable ? &open : NULL))
+    {
+        handle_function<void>(backend, callback);
+        ImGui::EndTabItem();
+    }
+    return open;
+};
+bool GuiDrawContext::win_tab_item_button(std::string label)
+{
+    // TODO: Which ImGuiTabItemFlags should be exposed? Many of them seem useful.
+    return ImGui::TabItemButton(label.c_str());
+};
 void GuiDrawContext::win_indent(float width)
 {
     if (std::abs(width) < 1.0f)
@@ -651,6 +676,9 @@ void register_usertypes(sol::state& lua)
     guidrawcontext_type["win_imagebutton"] = &GuiDrawContext::win_imagebutton;
     guidrawcontext_type["win_tooltip"] = &GuiDrawContext::win_tooltip;
     guidrawcontext_type["win_section"] = &GuiDrawContext::win_section;
+    guidrawcontext_type["win_tab_bar"] = &GuiDrawContext::win_tab_bar;
+    guidrawcontext_type["win_tab_item"] = &GuiDrawContext::win_tab_item;
+    guidrawcontext_type["win_tab_item_button"] = &GuiDrawContext::win_tab_item_button;
     guidrawcontext_type["win_indent"] = &GuiDrawContext::win_indent;
     guidrawcontext_type["win_width"] = &GuiDrawContext::win_width;
 

src/game_api/script/usertypes/gui_lua.hpp

@@ -120,6 +120,12 @@ class GuiDrawContext
     void win_tooltip(std::string text);
     /// Add a collapsing accordion section, put contents in the callback function.
     void win_section(std::string title, sol::function callback);
+    /// Add a tab bar. Only create tab items inside the callback.
+    void win_tab_bar(std::string id, sol::function callback);
+    /// Add a tab item. Only use this inside a tab bar callback. Returns false if closed from the X.
+    bool win_tab_item(std::string label, bool closeable, sol::function callback);
+    /// Add a tab item button. Only use this inside a tab bar callback. Returns true when clicked.
+    bool win_tab_item_button(std::string label);
     /// Indent contents, or unindent if negative
     void win_indent(float width);
     /// Sets next item width (width>1: width in pixels, width<0: to the right of window, -1<width<1: fractional, multiply by available window width)