Tables: Fixed PopItemWidth() or multi-components items not restoring per-colum ItemWidth correctly. (#3760) rework local stacks to facilitate modifying current value without altering the stack.

May consider doing the same for ItemFlags and moving to g.ItemFlags...

docs/CHANGELOG.txt

@@ -43,6 +43,7 @@ Breaking Changes:
 
 Other Changes:
 
+- Tables: Fixed PopItemWidth() or multi-components items not restoring per-colum ItemWidth correctly. (#3760)
 - Window: Fixed minor title bar text clipping issue when FramePadding is small/zero and there are no 
   close button in the window. (#3731)
 - imgui_freetype: Facilitated using FreeType integration: [@Xipiryon, @ocornut]

imgui.cpp

@@ -6428,15 +6428,15 @@ void ImGui::PopButtonRepeat()
 void ImGui::PushTextWrapPos(float wrap_pos_x)
 {
     ImGuiWindow* window = GetCurrentWindow();
+    window->DC.TextWrapPosStack.push_back(window->DC.TextWrapPos);
     window->DC.TextWrapPos = wrap_pos_x;
-    window->DC.TextWrapPosStack.push_back(wrap_pos_x);
 }
 
 void ImGui::PopTextWrapPos()
 {
     ImGuiWindow* window = GetCurrentWindow();
+    window->DC.TextWrapPos = window->DC.TextWrapPosStack.back();
     window->DC.TextWrapPosStack.pop_back();
-    window->DC.TextWrapPos = window->DC.TextWrapPosStack.empty() ? -1.0f : window->DC.TextWrapPosStack.back();
 }
 
 bool ImGui::IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent)
@@ -7393,12 +7393,13 @@ void ImGui::SetNextItemWidth(float item_width)
     g.NextItemData.Width = item_width;
 }
 
+// FIXME: Remove the == 0.0f behavior?
 void ImGui::PushItemWidth(float item_width)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
+    window->DC.ItemWidthStack.push_back(window->DC.ItemWidth); // Backup current width
     window->DC.ItemWidth = (item_width == 0.0f ? window->ItemWidthDefault : item_width);
-    window->DC.ItemWidthStack.push_back(window->DC.ItemWidth);
     g.NextItemData.Flags &= ~ImGuiNextItemDataFlags_HasWidth;
 }
 
@@ -7409,18 +7410,19 @@ void ImGui::PushMultiItemsWidths(int components, float w_full)
     const ImGuiStyle& style = g.Style;
     const float w_item_one  = ImMax(1.0f, IM_FLOOR((w_full - (style.ItemInnerSpacing.x) * (components - 1)) / (float)components));
     const float w_item_last = ImMax(1.0f, IM_FLOOR(w_full - (w_item_one + style.ItemInnerSpacing.x) * (components - 1)));
+    window->DC.ItemWidthStack.push_back(window->DC.ItemWidth); // Backup current width
     window->DC.ItemWidthStack.push_back(w_item_last);
-    for (int i = 0; i < components - 1; i++)
+    for (int i = 0; i < components - 2; i++)
         window->DC.ItemWidthStack.push_back(w_item_one);
-    window->DC.ItemWidth = window->DC.ItemWidthStack.back();
+    window->DC.ItemWidth = (components == 1) ? w_item_last : w_item_one;
     g.NextItemData.Flags &= ~ImGuiNextItemDataFlags_HasWidth;
 }
 
 void ImGui::PopItemWidth()
 {
     ImGuiWindow* window = GetCurrentWindow();
+    window->DC.ItemWidth = window->DC.ItemWidthStack.back();
     window->DC.ItemWidthStack.pop_back();
-    window->DC.ItemWidth = window->DC.ItemWidthStack.empty() ? window->ItemWidthDefault : window->DC.ItemWidthStack.back();
 }
 
 // Calculate default item width given value passed to PushItemWidth() or SetNextItemWidth().

imgui.h

@@ -59,7 +59,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.81 WIP"
-#define IMGUI_VERSION_NUM           18001
+#define IMGUI_VERSION_NUM           18002
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 
@@ -375,7 +375,7 @@ namespace ImGui
     IMGUI_API void          PopButtonRepeat();
 
     // Parameters stacks (current window)
-    IMGUI_API void          PushItemWidth(float item_width);                                // push width of items for common large "item+label" widgets. >0.0f: width in pixels, <0.0f align xx pixels to the right of window (so -FLT_MIN always align width to the right side). 0.0f = default to ~2/3 of windows width,
+    IMGUI_API void          PushItemWidth(float item_width);                                // push width of items for common large "item+label" widgets. >0.0f: width in pixels, <0.0f align xx pixels to the right of window (so -FLT_MIN always align width to the right side).
     IMGUI_API void          PopItemWidth();
     IMGUI_API void          SetNextItemWidth(float item_width);                             // set width of the _next_ common large "item+label" widget. >0.0f: width in pixels, <0.0f align xx pixels to the right of window (so -FLT_MIN always align width to the right side)
     IMGUI_API float         CalcItemWidth();                                                // width of item given pushed settings and current cursor position. NOT necessarily the width of last item unlike most 'Item' functions.

imgui_internal.h

@@ -1692,10 +1692,10 @@ struct IMGUI_API ImGuiWindowTempData
     // Local parameters stacks
     // We store the current settings outside of the vectors to increase memory locality (reduce cache misses). The vectors are rarely modified. Also it allows us to not heap allocate for short-lived windows which are not using those settings.
     ImGuiItemFlags          ItemFlags;              // == g.ItemFlagsStack.back()
-    float                   ItemWidth;              // == ItemWidthStack.back(). 0.0: default, >0.0: width in pixels, <0.0: align xx pixels to the right of window
-    float                   TextWrapPos;            // == TextWrapPosStack.back() [empty == -1.0f]
-    ImVector<float>         ItemWidthStack;
-    ImVector<float>         TextWrapPosStack;
+    float                   ItemWidth;              // Current item width (>0.0: width in pixels, <0.0: align xx pixels to the right of window).
+    float                   TextWrapPos;            // Current text wrap pos.
+    ImVector<float>         ItemWidthStack;         // Store item widths to restore (attention: .back() is not == ItemWidth)
+    ImVector<float>         TextWrapPosStack;       // Store text wrap pos to restore (attention: .back() is not == TextWrapPos)
     ImGuiStackSizes         StackSizesOnBegin;      // Store size of various stacks for asserting
 };