Tables: fixed resizing columns when using multiple synched instances that are layed out at different X positions. (#7933)

TableGetMaxColumnWidth() was using MinX from previous column. Storing info in column. Still incorrect interleaved data for multi-instances but it covers majority of use cases.

docs/CHANGELOG.txt

@@ -85,8 +85,8 @@ Other changes:
 - Tables: fixes/revert a 1.90 change were outer border would be moved bottom and right
   by an extra pixel + rework the change so that contents doesn't overlap the bottom and
   right border in a scrolling table. (#6765, #3752, #7428)
-- Tables: fixed an issue detecting hovering column/row when using multiple synched instances,
-  layed out at different X positions. (#7932)
+- Tables: fixed an issue resizing columns or querying hovered column/row when using multiple
+  synched instances that are layed out at different X positions. (#7933)
 - Tabs: avoid queuing a refocus when tab is already focused, which would have the
   side-effect of e.g. closing popup on a mouse release. (#7914)
 - InputText: allow callback to update buffer while in read-only mode. (imgui_club/#46)

imgui_internal.h

@@ -2827,6 +2827,7 @@ struct ImGuiTableColumn
     float                   MaxX;
     float                   WidthRequest;                   // Master width absolute value when !(Flags & _WidthStretch). When Stretch this is derived every frame from StretchWeight in TableUpdateLayout()
     float                   WidthAuto;                      // Automatic width
+    float                   WidthMax;                       // Maximum width (FIXME: overwritten by each instance)
     float                   StretchWeight;                  // Master width weight when (Flags & _WidthStretch). Often around ~1.0f initially.
     float                   InitStretchWeightOrWidth;       // Value passed to TableSetupColumn(). For Width it is a content width (_without padding_).
     ImRect                  ClipRect;                       // Clipping rectangle for the column
@@ -3470,7 +3471,7 @@ namespace ImGui
     IMGUI_API ImRect        TableGetCellBgRect(const ImGuiTable* table, int column_n);
     IMGUI_API const char*   TableGetColumnName(const ImGuiTable* table, int column_n);
     IMGUI_API ImGuiID       TableGetColumnResizeID(ImGuiTable* table, int column_n, int instance_no = 0);
-    IMGUI_API float         TableGetMaxColumnWidth(const ImGuiTable* table, int column_n);
+    IMGUI_API float         TableCalcMaxColumnWidth(const ImGuiTable* table, int column_n);
     IMGUI_API void          TableSetColumnWidthAutoSingle(ImGuiTable* table, int column_n);
     IMGUI_API void          TableSetColumnWidthAutoAll(ImGuiTable* table);
     IMGUI_API void          TableRemove(ImGuiTable* table);

imgui_tables.cpp

@@ -1074,8 +1074,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         column->MinX = offset_x;
 
         // Lock width based on start position and minimum/maximum width for this position
-        float max_width = TableGetMaxColumnWidth(table, column_n);
-        column->WidthGiven = ImMin(column->WidthGiven, max_width);
+        column->WidthMax = TableCalcMaxColumnWidth(table, column_n);
+        column->WidthGiven = ImMin(column->WidthGiven, column->WidthMax);
         column->WidthGiven = ImMax(column->WidthGiven, ImMin(column->WidthRequest, table->MinColumnWidth));
         column->MaxX = offset_x + column->WidthGiven + table->CellSpacingX1 + table->CellSpacingX2 + table->CellPaddingX * 2.0f;
 
@@ -2207,8 +2207,8 @@ void ImGui::TableEndCell(ImGuiTable* table)
 // Note that actual columns widths are computed in TableUpdateLayout().
 //-------------------------------------------------------------------------
 
-// Maximum column content width given current layout. Use column->MinX so this value on a per-column basis.
-float ImGui::TableGetMaxColumnWidth(const ImGuiTable* table, int column_n)
+// Maximum column content width given current layout. Use column->MinX so this value differs on a per-column basis.
+float ImGui::TableCalcMaxColumnWidth(const ImGuiTable* table, int column_n)
 {
     const ImGuiTableColumn* column = &table->Columns[column_n];
     float max_width = FLT_MAX;
@@ -2270,7 +2270,7 @@ void ImGui::TableSetColumnWidth(int column_n, float width)
     // Compare both requested and actual given width to avoid overwriting requested width when column is stuck (minimum size, bounded)
     IM_ASSERT(table->MinColumnWidth > 0.0f);
     const float min_width = table->MinColumnWidth;
-    const float max_width = ImMax(min_width, TableGetMaxColumnWidth(table, column_n));
+    const float max_width = ImMax(min_width, column_0->WidthMax); // Don't use TableCalcMaxColumnWidth() here as it would rely on MinX from last instance (#7933)
     column_0_width = ImClamp(column_0_width, min_width, max_width);
     if (column_0->WidthGiven == column_0_width || column_0->WidthRequest == column_0_width)
         return;