Tabs: added TabMinWidthBase, ImGuiStyleVar_TabMinWidthBase.

docs/CHANGELOG.txt

@@ -53,6 +53,9 @@ Other Changes:
 - Tables: fixed imgui_internal.h's TableGetHoveredRow() the same way. (#7350, #6588, #6250)
 - Tabs: fixed tab bar underline not drawing below scroll buttons, when
   they are enabled (minor regression from 1.90). (#6820, #4859, #5022, #5239)
+- Tabs: added style.TabMinWidthBase, ImGuiStyleVar_TabMinWidthBase to control
+  the base minimum width of a tab (default to 1.0f). This is the size before
+  any potential shrinking is applied.
 - Error Handling: minor improvements to error handling for TableGetSortSpecs()
   and TableSetBgColor() calls. (#1651, #8499)
 - Misc: fixed building with IMGUI_DISABLE_DEBUG_TOOLS only. (#8796)

imgui.cpp

@@ -1417,6 +1417,7 @@ ImGuiStyle::ImGuiStyle()
     ImageBorderSize             = 0.0f;             // Thickness of border around tabs.
     TabRounding                 = 5.0f;             // Radius of upper corners of a tab. Set to 0.0f to have rectangular tabs.
     TabBorderSize               = 0.0f;             // Thickness of border around tabs.
+    TabMinWidthBase             = 1.0f;             // Minimum tab width, to make tabs larger than their contents. TabBar buttons are not affected.
     TabCloseButtonMinWidthSelected   = -1.0f;       // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width.
     TabCloseButtonMinWidthUnselected = 0.0f;        // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width. FLT_MAX: never show close button when unselected.
     TabBarBorderSize            = 1.0f;             // Thickness of tab-bar separator, which takes on the tab active color to denote focus.
@@ -1483,6 +1484,7 @@ void ImGuiStyle::ScaleAllSizes(float scale_factor)
     LogSliderDeadzone = ImTrunc(LogSliderDeadzone * scale_factor);
     ImageBorderSize = ImTrunc(ImageBorderSize * scale_factor);
     TabRounding = ImTrunc(TabRounding * scale_factor);
+    TabMinWidthBase = ImTrunc(TabMinWidthBase * scale_factor);
     TabCloseButtonMinWidthSelected = (TabCloseButtonMinWidthSelected > 0.0f && TabCloseButtonMinWidthSelected != FLT_MAX) ? ImTrunc(TabCloseButtonMinWidthSelected * scale_factor) : TabCloseButtonMinWidthSelected;
     TabCloseButtonMinWidthUnselected = (TabCloseButtonMinWidthUnselected > 0.0f && TabCloseButtonMinWidthUnselected != FLT_MAX) ? ImTrunc(TabCloseButtonMinWidthUnselected * scale_factor) : TabCloseButtonMinWidthUnselected;
     TabBarOverlineSize = ImTrunc(TabBarOverlineSize * scale_factor);
@@ -3502,6 +3504,7 @@ static const ImGuiStyleVarInfo GStyleVarsInfo[] =
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, ImageBorderSize) },           // ImGuiStyleVar_ImageBorderSize
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TabRounding) },               // ImGuiStyleVar_TabRounding
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TabBorderSize) },             // ImGuiStyleVar_TabBorderSize
+    { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TabMinWidthBase) },           // ImGuiStyleVar_TabMinWidthBase
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TabBarBorderSize) },          // ImGuiStyleVar_TabBarBorderSize
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TabBarOverlineSize) },        // ImGuiStyleVar_TabBarOverlineSize
     { 1, ImGuiDataType_Float, (ImU32)offsetof(ImGuiStyle, TableAngledHeadersAngle)},    // ImGuiStyleVar_TableAngledHeadersAngle

imgui.h

@@ -1803,6 +1803,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_ImageBorderSize,          // float     ImageBorderSize
     ImGuiStyleVar_TabRounding,              // float     TabRounding
     ImGuiStyleVar_TabBorderSize,            // float     TabBorderSize
+    ImGuiStyleVar_TabMinWidthBase,          // float     TabMinWidthBase
     ImGuiStyleVar_TabBarBorderSize,         // float     TabBarBorderSize
     ImGuiStyleVar_TabBarOverlineSize,       // float     TabBarOverlineSize
     ImGuiStyleVar_TableAngledHeadersAngle,  // float     TableAngledHeadersAngle
@@ -2268,6 +2269,7 @@ struct ImGuiStyle
     float       ImageBorderSize;            // Thickness of border around Image() calls.
     float       TabRounding;                // Radius of upper corners of a tab. Set to 0.0f to have rectangular tabs.
     float       TabBorderSize;              // Thickness of border around tabs.
+    float       TabMinWidthBase;            // Minimum tab width, to make tabs larger than their contents. TabBar buttons are not affected.
     float       TabCloseButtonMinWidthSelected;     // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width.
     float       TabCloseButtonMinWidthUnselected;   // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width. FLT_MAX: never show close button when unselected.
     float       TabBarBorderSize;           // Thickness of tab-bar separator, which takes on the tab active color to denote focus.

imgui_demo.cpp

@@ -8341,8 +8341,9 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             SliderFloat("TabBarBorderSize", &style.TabBarBorderSize, 0.0f, 2.0f, "%.0f");
             SliderFloat("TabBarOverlineSize", &style.TabBarOverlineSize, 0.0f, 3.0f, "%.0f");
             SameLine(); HelpMarker("Overline is only drawn over the selected tab when ImGuiTabBarFlags_DrawSelectedOverline is set.");
-            DragFloat("TabCloseButtonMinWidthSelected", &style.TabCloseButtonMinWidthSelected, 0.1f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthSelected < 0.0f) ? "%.0f (Always)" : "%.0f");
-            DragFloat("TabCloseButtonMinWidthUnselected", &style.TabCloseButtonMinWidthUnselected, 0.1f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthUnselected < 0.0f) ? "%.0f (Always)" : "%.0f");
+            DragFloat("TabMinWidthBase", &style.TabMinWidthBase, 0.5f, 1.0f, 500.0f, "%.0f");
+            DragFloat("TabCloseButtonMinWidthSelected", &style.TabCloseButtonMinWidthSelected, 0.5f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthSelected < 0.0f) ? "%.0f (Always)" : "%.0f");
+            DragFloat("TabCloseButtonMinWidthUnselected", &style.TabCloseButtonMinWidthUnselected, 0.5f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthUnselected < 0.0f) ? "%.0f (Always)" : "%.0f");
             SliderFloat("TabRounding", &style.TabRounding, 0.0f, 12.0f, "%.0f");
 
             SeparatorText("Tables");

imgui_internal.h

@@ -2735,7 +2735,7 @@ struct ImGuiTabItem
     int                 LastFrameSelected;      // This allows us to infer an ordered list of the last activated tabs with little maintenance
     float               Offset;                 // Position relative to beginning of tab
     float               Width;                  // Width currently displayed
-    float               ContentWidth;           // Width of label, stored during BeginTabItem() call
+    float               ContentWidth;           // Width of label + padding, stored during BeginTabItem() call (misnamed as "Content" would normally imply width of label only)
     float               RequestedWidth;         // Width optionally requested by caller, -1.0f is unused
     ImS32               NameOffset;             // When Window==NULL, offset to name within parent ImGuiTabBar::TabsNames
     ImS16               BeginOrder;             // BeginTabItem() order, used to re-order tabs after toggling ImGuiTabBarFlags_Reorderable

imgui_widgets.cpp

@@ -9648,6 +9648,8 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
         const char* tab_name = TabBarGetTabName(tab_bar, tab);
         const bool has_close_button_or_unsaved_marker = (tab->Flags & ImGuiTabItemFlags_NoCloseButton) == 0 || (tab->Flags & ImGuiTabItemFlags_UnsavedDocument);
         tab->ContentWidth = (tab->RequestedWidth >= 0.0f) ? tab->RequestedWidth : TabItemCalcSize(tab_name, has_close_button_or_unsaved_marker).x;
+        if ((tab->Flags & ImGuiTabItemFlags_Button) == 0)
+            tab->ContentWidth = ImMax(tab->ContentWidth, g.Style.TabMinWidthBase);
 
         int section_n = TabItemGetSectionIdx(tab);
         ImGuiTabBarSection* section = &sections[section_n];