Internals: TabBar renaming and shuffling stuff around.

+ sneaking a readme change

docs/README.md

@@ -115,7 +115,7 @@ Officially maintained bindings (in repository):
 
 Third-party bindings (see [Bindings](https://github.com/ocornut/imgui/wiki/Bindings/) page):
 - Languages: C, C# and: Beef, ChaiScript, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lua, Odin, Pascal, PureBasic, Python, Ruby, Rust, Swift...
-- Frameworks: AGS/Adventure Game Studio, Amethyst, bsf, Cinder, Cocos2d-x, Diligent Engine, Flexium, GML/Game Maker Studio2, Godot, GTK3+OpenGL3, Irrlicht Engine, LÖVE+LUA, Magnum, NanoRT, Nim Game Lib, Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, SFML, Sokol, Unity, Unreal Engine 4, vtk, Win32 GDI, WxWidgets.
+- Frameworks: AGS/Adventure Game Studio, Amethyst, bsf, Cinder, Cocos2d-x, Diligent Engine, Flexium, GML/Game Maker Studio2, Godot, GTK3+OpenGL3, Irrlicht Engine, LÖVE+LUA, Magnum, NanoRT, nCine, Nim Game Lib, Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, SFML, Sokol, Unity, Unreal Engine 4, vtk, Win32 GDI, WxWidgets.
 - Note that C bindings ([cimgui](https://github.com/cimgui/cimgui)) are auto-generated, you can use its json/lua output to generate bindings for other languages.
 
 Also see [Wiki](https://github.com/ocornut/imgui/wiki) for more links and ideas.

imgui.cpp

@@ -10504,8 +10504,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 {
                     const ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
                     ImGui::PushID(tab);
-                    if (ImGui::SmallButton("<")) { TabBarQueueChangeTabOrder(tab_bar, tab, -1); } ImGui::SameLine(0, 2);
-                    if (ImGui::SmallButton(">")) { TabBarQueueChangeTabOrder(tab_bar, tab, +1); } ImGui::SameLine();
+                    if (ImGui::SmallButton("<")) { TabBarQueueReorder(tab_bar, tab, -1); } ImGui::SameLine(0, 2);
+                    if (ImGui::SmallButton(">")) { TabBarQueueReorder(tab_bar, tab, +1); } ImGui::SameLine();
                     ImGui::Text("%02d%c Tab 0x%08X '%s'", tab_n, (tab->ID == tab_bar->SelectedTabId) ? '*' : ' ', tab->ID, (tab->NameOffset != -1) ? tab_bar->GetTabName(tab) : "");
                     ImGui::PopID();
                 }

imgui_internal.h

@@ -1731,8 +1731,8 @@ struct ImGuiTabBar
     int                 PrevFrameVisible;
     ImRect              BarRect;
     float               LastTabContentHeight;   // Record the height of contents submitted below the tab bar
-    float               OffsetMax;              // Distance from BarRect.Min.x, locked during layout
-    float               OffsetMaxIdeal;         // Ideal offset if all tabs were visible and not clipped
+    float               WidthAllTabs;           // Actual width of all tabs (locked during layout)
+    float               WidthAllTabsIdeal;      // Ideal width if all tabs were visible and not clipped
     float               OffsetNextTab;          // Distance from BarRect.Min.x, incremented with each BeginTabItem() call, not used if ImGuiTabBarFlags_Reorderable if set.
     float               ScrollingAnim;
     float               ScrollingTarget;
@@ -1931,7 +1931,8 @@ namespace ImGui
     IMGUI_API ImGuiTabItem* TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API void          TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API void          TabBarCloseTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
-    IMGUI_API void          TabBarQueueChangeTabOrder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int dir);
+    IMGUI_API void          TabBarQueueReorder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int dir);
+    IMGUI_API bool          TabBarProcessReorder(ImGuiTabBar* tab_bar);
     IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);

imgui_widgets.cpp

@@ -6761,7 +6761,7 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool* p_selected,
 // - TabBarFindTabById() [Internal]
 // - TabBarRemoveTab() [Internal]
 // - TabBarCloseTab() [Internal]
-// - TabBarScrollClamp()v
+// - TabBarScrollClamp() [Internal]
 // - TabBarScrollToTab() [Internal]
 // - TabBarQueueChangeTabOrder() [Internal]
 // - TabBarScrollingButtons() [Internal]
@@ -6785,7 +6785,7 @@ ImGuiTabBar::ImGuiTabBar()
     SelectedTabId = NextSelectedTabId = VisibleTabId = 0;
     CurrFrameVisible = PrevFrameVisible = -1;
     LastTabContentHeight = 0.0f;
-    OffsetMax = OffsetMaxIdeal = OffsetNextTab = 0.0f;
+    WidthAllTabs = WidthAllTabsIdeal = OffsetNextTab = 0.0f;
     ScrollingAnim = ScrollingTarget = ScrollingTargetDistToVisibility = ScrollingSpeed = 0.0f;
     Flags = ImGuiTabBarFlags_None;
     ReorderRequestTabId = 0;
@@ -6951,23 +6951,9 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
     // Process order change request (we could probably process it when requested but it's just saner to do it in a single spot).
     if (tab_bar->ReorderRequestTabId != 0)
     {
-        if (ImGuiTabItem* tab1 = TabBarFindTabByID(tab_bar, tab_bar->ReorderRequestTabId))
-        {
-            //IM_ASSERT(tab_bar->Flags & ImGuiTabBarFlags_Reorderable); // <- this may happen when using debug tools
-            int tab2_order = tab_bar->GetTabOrder(tab1) + tab_bar->ReorderRequestDir;
-            if (tab2_order >= 0 && tab2_order < tab_bar->Tabs.Size)
-            {
-                ImGuiTabItem* tab2 = &tab_bar->Tabs[tab2_order];
-                ImGuiTabItem item_tmp = *tab1;
-                *tab1 = *tab2;
-                *tab2 = item_tmp;
-                if (tab2->ID == tab_bar->SelectedTabId)
-                    scroll_track_selected_tab_id = tab2->ID;
-                tab1 = tab2 = NULL;
-            }
-            if (tab_bar->Flags & ImGuiTabBarFlags_SaveSettings)
-                MarkIniSettingsDirty();
-        }
+        if (TabBarProcessReorder(tab_bar))
+            if (tab_bar->ReorderRequestTabId == tab_bar->SelectedTabId)
+                scroll_track_selected_tab_id = tab_bar->ReorderRequestTabId;
         tab_bar->ReorderRequestTabId = 0;
     }
 
@@ -7041,11 +7027,11 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
         offset_x += tab->Width + g.Style.ItemInnerSpacing.x;
         offset_x_ideal += tab->ContentWidth + g.Style.ItemInnerSpacing.x;
     }
-    tab_bar->OffsetMax = ImMax(offset_x - g.Style.ItemInnerSpacing.x, 0.0f);
-    tab_bar->OffsetMaxIdeal = ImMax(offset_x_ideal - g.Style.ItemInnerSpacing.x, 0.0f);
+    tab_bar->WidthAllTabs = ImMax(offset_x - g.Style.ItemInnerSpacing.x, 0.0f);
+    tab_bar->WidthAllTabsIdeal = ImMax(offset_x_ideal - g.Style.ItemInnerSpacing.x, 0.0f);
 
     // Horizontal scrolling buttons
-    const bool scrolling_buttons = (tab_bar->OffsetMax > tab_bar->BarRect.GetWidth() && tab_bar->Tabs.Size > 1) && !(tab_bar->Flags & ImGuiTabBarFlags_NoTabListScrollingButtons) && (tab_bar->Flags & ImGuiTabBarFlags_FittingPolicyScroll);
+    const bool scrolling_buttons = (tab_bar->WidthAllTabs > tab_bar->BarRect.GetWidth() && tab_bar->Tabs.Size > 1) && !(tab_bar->Flags & ImGuiTabBarFlags_NoTabListScrollingButtons) && (tab_bar->Flags & ImGuiTabBarFlags_FittingPolicyScroll);
     if (scrolling_buttons)
         if (ImGuiTabItem* tab_to_select = TabBarScrollingButtons(tab_bar)) // NB: Will alter BarRect.Max.x!
             scroll_track_selected_tab_id = tab_bar->SelectedTabId = tab_to_select->ID;
@@ -7087,7 +7073,7 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
     // Actual layout in host window (we don't do it in BeginTabBar() so as not to waste an extra frame)
     ImGuiWindow* window = g.CurrentWindow;
     window->DC.CursorPos = tab_bar->BarRect.Min;
-    ItemSize(ImVec2(tab_bar->OffsetMaxIdeal, tab_bar->BarRect.GetHeight()), tab_bar->FramePadding.y);
+    ItemSize(ImVec2(tab_bar->WidthAllTabsIdeal, tab_bar->BarRect.GetHeight()), tab_bar->FramePadding.y);
 }
 
 // Dockables uses Name/ID in the global namespace. Non-dockable items use the ID stack.
@@ -7150,7 +7136,7 @@ void ImGui::TabBarCloseTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab)
 
 static float ImGui::TabBarScrollClamp(ImGuiTabBar* tab_bar, float scrolling)
 {
-    scrolling = ImMin(scrolling, tab_bar->OffsetMax - tab_bar->BarRect.GetWidth());
+    scrolling = ImMin(scrolling, tab_bar->WidthAllTabs - tab_bar->BarRect.GetWidth());
     return ImMax(scrolling, 0.0f);
 }
 
@@ -7174,7 +7160,7 @@ static void ImGui::TabBarScrollToTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab)
     }
 }
 
-void ImGui::TabBarQueueChangeTabOrder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int dir)
+void ImGui::TabBarQueueReorder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int dir)
 {
     IM_ASSERT(dir == -1 || dir == +1);
     IM_ASSERT(tab_bar->ReorderRequestTabId == 0);
@@ -7182,6 +7168,28 @@ void ImGui::TabBarQueueChangeTabOrder(ImGuiTabBar* tab_bar, const ImGuiTabItem*
     tab_bar->ReorderRequestDir = (ImS8)dir;
 }
 
+bool ImGui::TabBarProcessReorder(ImGuiTabBar* tab_bar)
+{
+    ImGuiTabItem* tab1 = TabBarFindTabByID(tab_bar, tab_bar->ReorderRequestTabId);
+    if (!tab1)
+        return false;
+
+    //IM_ASSERT(tab_bar->Flags & ImGuiTabBarFlags_Reorderable); // <- this may happen when using debug tools
+    int tab2_order = tab_bar->GetTabOrder(tab1) + tab_bar->ReorderRequestDir;
+    if (tab2_order < 0 || tab2_order >= tab_bar->Tabs.Size)
+        return false;
+
+    ImGuiTabItem* tab2 = &tab_bar->Tabs[tab2_order];
+    ImGuiTabItem item_tmp = *tab1;
+    *tab1 = *tab2;
+    *tab2 = item_tmp;
+    tab1 = tab2 = NULL;
+
+    if (tab_bar->Flags & ImGuiTabBarFlags_SaveSettings)
+        MarkIniSettingsDirty();
+    return true;
+}
+
 static ImGuiTabItem* ImGui::TabBarScrollingButtons(ImGuiTabBar* tab_bar)
 {
     ImGuiContext& g = *GImGui;
@@ -7293,7 +7301,7 @@ bool    ImGui::BeginTabItem(const char* label, bool* p_open, ImGuiTabItemFlags f
     ImGuiTabBar* tab_bar = g.CurrentTabBar;
     if (tab_bar == NULL)
     {
-        IM_ASSERT_USER_ERROR(tab_bar, "BeginTabItem() Needs to be called between BeginTabBar() and EndTabBar()!");
+        IM_ASSERT_USER_ERROR(tab_bar, "Needs to be called between BeginTabBar() and EndTabBar()!");
         return false;
     }
     bool ret = TabItemEx(tab_bar, label, p_open, flags);
@@ -7315,7 +7323,7 @@ void    ImGui::EndTabItem()
     ImGuiTabBar* tab_bar = g.CurrentTabBar;
     if (tab_bar == NULL)
     {
-        IM_ASSERT(tab_bar != NULL && "Needs to be called between BeginTabBar() and EndTabBar()!");
+        IM_ASSERT_USER_ERROR(tab_bar != NULL, "Needs to be called between BeginTabBar() and EndTabBar()!");
         return;
     }
     IM_ASSERT(tab_bar->LastTabItemIdx >= 0);
@@ -7471,12 +7479,12 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
             if (g.IO.MouseDelta.x < 0.0f && g.IO.MousePos.x < bb.Min.x)
             {
                 if (tab_bar->Flags & ImGuiTabBarFlags_Reorderable)
-                    TabBarQueueChangeTabOrder(tab_bar, tab, -1);
+                    TabBarQueueReorder(tab_bar, tab, -1);
             }
             else if (g.IO.MouseDelta.x > 0.0f && g.IO.MousePos.x > bb.Max.x)
             {
                 if (tab_bar->Flags & ImGuiTabBarFlags_Reorderable)
-                    TabBarQueueChangeTabOrder(tab_bar, tab, +1);
+                    TabBarQueueReorder(tab_bar, tab, +1);
             }
         }
     }