Internals: Columns: Poke into WorkRect and use them in the GetContentRegionMax() functions. This should be a no-op, but preparing us to transition toward using WorkRect instead of ContentRegionRect.

Removed one use of ContentsRegionRect.

imgui.cpp

@@ -2249,8 +2249,8 @@ static void SetCursorPosYAndSetupDummyPrevLine(float pos_y, float line_height)
     ImGuiWindow* window = ImGui::GetCurrentWindow();
     window->DC.CursorPosPrevLine.y = window->DC.CursorPos.y - line_height;      // Setting those fields so that SetScrollHereY() can properly function after the end of our clipper usage.
     window->DC.PrevLineSize.y = (line_height - GImGui->Style.ItemSpacing.y);    // If we end up needing more accurate data (to e.g. use SameLine) we may as well make the clipper have a fourth step to let user process and display the last item in their list.
-    if (window->DC.CurrentColumns)
-        window->DC.CurrentColumns->LineMinY = window->DC.CursorPos.y;           // Setting this so that cell Y position are set properly
+    if (ImGuiColumns* columns = window->DC.CurrentColumns)
+        columns->LineMinY = window->DC.CursorPos.y;                             // Setting this so that cell Y position are set properly
 }
 
 // Use case A: Begin() called from constructor with items_height<0, then called again from Sync() in StepNo 1
@@ -3423,7 +3423,7 @@ void ImGui::UpdateMouseWheel()
     const bool scroll_allowed = !(window->Flags & ImGuiWindowFlags_NoScrollWithMouse) && !(window->Flags & ImGuiWindowFlags_NoMouseInputs);
     if (scroll_allowed && (g.IO.MouseWheel != 0.0f || g.IO.MouseWheelH != 0.0f) && !g.IO.KeyCtrl)
     {
-        ImVec2 max_step = (window->ContentsRegionRect.GetSize() + window->WindowPadding * 2.0f) * 0.67f;
+        ImVec2 max_step = window->InnerRect.GetSize() * 0.67f;
 
         // Vertical Mouse Wheel Scrolling (hold Shift to scroll horizontally)
         if (g.IO.MouseWheel != 0.0f && !g.IO.KeyShift)
@@ -5872,7 +5872,7 @@ void ImGui::End()
 
     ImGuiWindow* window = g.CurrentWindow;
 
-    if (window->DC.CurrentColumns != NULL)
+    if (window->DC.CurrentColumns)
         EndColumns();
     PopClipRect();   // Inner window clip rectangle
 
@@ -6649,7 +6649,7 @@ ImVec2 ImGui::GetContentRegionMax()
     ImGuiWindow* window = GImGui->CurrentWindow;
     ImVec2 mx = window->ContentsRegionRect.Max - window->Pos;
     if (window->DC.CurrentColumns)
-        mx.x = GetColumnOffset(window->DC.CurrentColumns->Current + 1) - window->WindowPadding.x;
+        mx.x = window->WorkRect.Max.x - window->Pos.x;
     return mx;
 }
 
@@ -6659,7 +6659,7 @@ ImVec2 ImGui::GetContentRegionMaxAbs()
     ImGuiWindow* window = GImGui->CurrentWindow;
     ImVec2 mx = window->ContentsRegionRect.Max;
     if (window->DC.CurrentColumns)
-        mx.x = window->Pos.x + GetColumnOffset(window->DC.CurrentColumns->Current + 1) - window->WindowPadding.x;
+        mx.x = window->WorkRect.Max.x;
     return mx;
 }
 
@@ -6672,19 +6672,19 @@ ImVec2 ImGui::GetContentRegionAvail()
 // In window space (not screen space!)
 ImVec2 ImGui::GetWindowContentRegionMin()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     return window->ContentsRegionRect.Min - window->Pos;
 }
 
 ImVec2 ImGui::GetWindowContentRegionMax()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     return window->ContentsRegionRect.Max - window->Pos;
 }
 
 float ImGui::GetWindowContentRegionWidth()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     return window->ContentsRegionRect.GetWidth();
 }
 
@@ -8655,7 +8655,13 @@ void ImGui::NextColumn()
     window->DC.CurrLineTextBaseOffset = 0.0f;
 
     PushColumnClipRect(columns->Current);     // FIXME-COLUMNS: Could it be an overwrite?
-    PushItemWidth(GetColumnWidth() * 0.65f);  // FIXME-COLUMNS: Move on columns setup
+
+    // FIXME-COLUMNS: Share code with BeginColumns() - move code on columns setup.
+    float offset_0 = GetColumnOffset(columns->Current);
+    float offset_1 = GetColumnOffset(columns->Current + 1);
+    float width = offset_1 - offset_0;
+    PushItemWidth(width * 0.65f);
+    window->WorkRect.Max.x = window->Pos.x + offset_1 - window->WindowPadding.x;
 }
 
 int ImGui::GetColumnIndex()
@@ -8851,6 +8857,7 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
     columns->HostCursorPosY = window->DC.CursorPos.y;
     columns->HostCursorMaxPosX = window->DC.CursorMaxPos.x;
     columns->HostClipRect = window->ClipRect;
+    columns->HostWorkRect = window->WorkRect;
     columns->LineMinY = columns->LineMaxY = window->DC.CursorPos.y;
     window->DC.ColumnsOffset.x = 0.0f;
     window->DC.CursorPos.x = (float)(int)(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
@@ -8888,7 +8895,12 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
         window->DrawList->ChannelsSetCurrent(1);
         PushColumnClipRect(0);
     }
-    PushItemWidth(GetColumnWidth() * 0.65f);
+
+    float offset_0 = GetColumnOffset(columns->Current);
+    float offset_1 = GetColumnOffset(columns->Current + 1);
+    float width = offset_1 - offset_0;
+    PushItemWidth(width * 0.65f);
+    window->WorkRect.Max.x = window->Pos.x + offset_1 - window->WindowPadding.x;
 }
 
 void ImGui::EndColumns()
@@ -8960,6 +8972,7 @@ void ImGui::EndColumns()
     }
     columns->IsBeingResized = is_being_resized;
 
+    window->WorkRect = columns->HostWorkRect;
     window->DC.CurrentColumns = NULL;
     window->DC.ColumnsOffset.x = 0.0f;
     window->DC.CursorPos.x = (float)(int)(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);

imgui_internal.h

@@ -703,6 +703,7 @@ struct ImGuiColumns
     float               HostCursorPosY;         // Backup of CursorPos at the time of BeginColumns()
     float               HostCursorMaxPosX;      // Backup of CursorMaxPos at the time of BeginColumns()
     ImRect              HostClipRect;           // Backup of ClipRect at the time of BeginColumns()
+    ImRect              HostWorkRect;           // Backup of WorkRect at the time of BeginColumns()
     ImVector<ImGuiColumnData> Columns;
 
     ImGuiColumns()      { Clear(); }
@@ -1298,7 +1299,7 @@ struct IMGUI_API ImGuiWindow
     // The best way to understand what those rectangles are is to use the 'Metrics -> Tools -> Show windows rectangles' viewer.
     // The main 'OuterRect', omitted as a field, is window->Rect().
     ImRect                  OuterRectClipped;                   // == Window->Rect() just after setup in Begin(). == window->Rect() for root window.
-    ImRect                  InnerRect;                          // Inner rectangle (omit title bar, menu bar)
+    ImRect                  InnerRect;                          // Inner rectangle (omit title bar, menu bar, scroll bar)
     ImRect                  InnerClipRect;                      // == InnerRect shrunk by WindowPadding*0.5f on each side, clipped within viewport or parent clip rect.
     ImRect                  WorkRect;                           // Cover the whole scrolling region, shrunk by WindowPadding*1.0f on each side. This is meant to replace ContentsRegionRect over time (from 1.71+ onward).
     ImRect                  ClipRect;                           // Current clipping/scissoring rectangle, evolve as we are using PushClipRect(), etc. == DrawList->clip_rect_stack.back().