Internals: Layout: maintain two content sizes, optionally writing to IdealMaxPos to distinguish used from ideal size, later is used for auto-fit. Unused in this commit, should be no-op. (#3414)

# Conflicts:
#	imgui.cpp

imgui.cpp

@@ -5048,18 +5048,24 @@ static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size
     return new_size;
 }
 
-static ImVec2 CalcWindowContentSize(ImGuiWindow* window)
+static void CalcWindowContentSizes(ImGuiWindow* window, ImVec2* content_size_current, ImVec2* content_size_ideal)
 {
-    if (window->Collapsed)
-        if (window->AutoFitFramesX <= 0 && window->AutoFitFramesY <= 0)
-            return window->ContentSize;
-    if (window->Hidden && window->HiddenFramesCannotSkipItems == 0 && window->HiddenFramesCanSkipItems > 0)
-        return window->ContentSize;
+    bool preserve_old_content_sizes = false;
+    if (window->Collapsed && window->AutoFitFramesX <= 0 && window->AutoFitFramesY <= 0)
+        preserve_old_content_sizes = true;
+    else if (window->Hidden && window->HiddenFramesCannotSkipItems == 0 && window->HiddenFramesCanSkipItems > 0)
+        preserve_old_content_sizes = true;
+    if (preserve_old_content_sizes)
+    {
+        *content_size_current = window->ContentSize;
+        *content_size_ideal = window->ContentSizeIdeal;
+        return;
+    }
 
-    ImVec2 sz;
-    sz.x = IM_FLOOR((window->ContentSizeExplicit.x != 0.0f) ? window->ContentSizeExplicit.x : window->DC.CursorMaxPos.x - window->DC.CursorStartPos.x);
-    sz.y = IM_FLOOR((window->ContentSizeExplicit.y != 0.0f) ? window->ContentSizeExplicit.y : window->DC.CursorMaxPos.y - window->DC.CursorStartPos.y);
-    return sz;
+    content_size_current->x = (window->ContentSizeExplicit.x != 0.0f) ? window->ContentSizeExplicit.x : IM_FLOOR(window->DC.CursorMaxPos.x - window->DC.CursorStartPos.x);
+    content_size_current->y = (window->ContentSizeExplicit.y != 0.0f) ? window->ContentSizeExplicit.y : IM_FLOOR(window->DC.CursorMaxPos.y - window->DC.CursorStartPos.y);
+    content_size_ideal->x = (window->ContentSizeExplicit.x != 0.0f) ? window->ContentSizeExplicit.x : IM_FLOOR(ImMax(window->DC.CursorMaxPos.x, window->DC.IdealMaxPos.x) - window->DC.CursorStartPos.x);
+    content_size_ideal->y = (window->ContentSizeExplicit.y != 0.0f) ? window->ContentSizeExplicit.y : IM_FLOOR(ImMax(window->DC.CursorMaxPos.y, window->DC.IdealMaxPos.y) - window->DC.CursorStartPos.y);
 }
 
 static ImVec2 CalcWindowAutoFitSize(ImGuiWindow* window, const ImVec2& size_contents)
@@ -5097,10 +5103,12 @@ static ImVec2 CalcWindowAutoFitSize(ImGuiWindow* window, const ImVec2& size_cont
     }
 }
 
-ImVec2 ImGui::CalcWindowExpectedSize(ImGuiWindow* window)
+ImVec2 ImGui::CalcWindowNextAutoFitSize(ImGuiWindow* window)
 {
-    ImVec2 size_contents = CalcWindowContentSize(window);
-    ImVec2 size_auto_fit = CalcWindowAutoFitSize(window, size_contents);
+    ImVec2 size_contents_current;
+    ImVec2 size_contents_ideal;
+    CalcWindowContentSizes(window, &size_contents_current, &size_contents_ideal);
+    ImVec2 size_auto_fit = CalcWindowAutoFitSize(window, size_contents_ideal);
     ImVec2 size_final = CalcWindowSizeAfterConstraint(window, size_auto_fit);
     return size_final;
 }
@@ -5697,7 +5705,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // UPDATE CONTENTS SIZE, UPDATE HIDDEN STATUS
 
         // Update contents size from last frame for auto-fitting (or use explicit size)
-        window->ContentSize = CalcWindowContentSize(window);
+        CalcWindowContentSizes(window, &window->ContentSize, &window->ContentSizeIdeal);
         if (window->HiddenFramesCanSkipItems > 0)
             window->HiddenFramesCanSkipItems--;
         if (window->HiddenFramesCannotSkipItems > 0)
@@ -5720,7 +5728,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
                     window->Size.x = window->SizeFull.x = 0.f;
                 if (!window_size_y_set_by_api)
                     window->Size.y = window->SizeFull.y = 0.f;
-                window->ContentSize = ImVec2(0.f, 0.f);
+                window->ContentSize = window->ContentSizeIdeal = ImVec2(0.f, 0.f);
             }
         }
 
@@ -5766,7 +5774,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // SIZE
 
         // Calculate auto-fit size, handle automatic resize
-        const ImVec2 size_auto_fit = CalcWindowAutoFitSize(window, window->ContentSize);
+        const ImVec2 size_auto_fit = CalcWindowAutoFitSize(window, window->ContentSizeIdeal);
         bool use_current_size_for_scrollbar_x = window_just_created;
         bool use_current_size_for_scrollbar_y = window_just_created;
         if ((flags & ImGuiWindowFlags_AlwaysAutoResize) && !window->Collapsed)
@@ -6053,6 +6061,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->DC.CursorPos = window->DC.CursorStartPos;
         window->DC.CursorPosPrevLine = window->DC.CursorPos;
         window->DC.CursorMaxPos = window->DC.CursorStartPos;
+        window->DC.IdealMaxPos = window->DC.CursorStartPos;
         window->DC.CurrLineSize = window->DC.PrevLineSize = ImVec2(0.0f, 0.0f);
         window->DC.CurrLineTextBaseOffset = window->DC.PrevLineTextBaseOffset = 0.0f;
 
@@ -6698,7 +6707,7 @@ void ImGui::SetNextWindowContentSize(const ImVec2& size)
 {
     ImGuiContext& g = *GImGui;
     g.NextWindowData.Flags |= ImGuiNextWindowDataFlags_HasContentSize;
-    g.NextWindowData.ContentSizeVal = size;
+    g.NextWindowData.ContentSizeVal = ImFloor(size);
 }
 
 void ImGui::SetNextWindowScroll(const ImVec2& scroll)
@@ -10544,8 +10553,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
     Separator();
 
     // Debugging enums
-    enum { WRT_OuterRect, WRT_OuterRectClipped, WRT_InnerRect, WRT_InnerClipRect, WRT_WorkRect, WRT_Content, WRT_ContentRegionRect, WRT_Count }; // Windows Rect Type
-    const char* wrt_rects_names[WRT_Count] = { "OuterRect", "OuterRectClipped", "InnerRect", "InnerClipRect", "WorkRect", "Content", "ContentRegionRect" };
+    enum { WRT_OuterRect, WRT_OuterRectClipped, WRT_InnerRect, WRT_InnerClipRect, WRT_WorkRect, WRT_Content, WRT_ContentIdeal, WRT_ContentRegionRect, WRT_Count }; // Windows Rect Type
+    const char* wrt_rects_names[WRT_Count] = { "OuterRect", "OuterRectClipped", "InnerRect", "InnerClipRect", "WorkRect", "Content", "ContentIdeal", "ContentRegionRect" };
     enum { TRT_OuterRect, TRT_InnerRect, TRT_WorkRect, TRT_HostClipRect, TRT_InnerClipRect, TRT_BackgroundClipRect, TRT_ColumnsRect, TRT_ColumnsWorkRect, TRT_ColumnsClipRect, TRT_ColumnsContentHeadersUsed, TRT_ColumnsContentHeadersIdeal, TRT_ColumnsContentFrozen, TRT_ColumnsContentUnfrozen, TRT_Count }; // Tables Rect Type
     const char* trt_rects_names[TRT_Count] = { "OuterRect", "InnerRect", "WorkRect", "HostClipRect", "InnerClipRect", "BackgroundClipRect", "ColumnsRect", "ColumnsWorkRect", "ColumnsClipRect", "ColumnsContentHeadersUsed", "ColumnsContentHeadersIdeal", "ColumnsContentFrozen", "ColumnsContentUnfrozen" };
     if (cfg->ShowWindowsRectsType < 0)
@@ -10581,7 +10590,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             else if (rect_type == WRT_InnerRect)            { return window->InnerRect; }
             else if (rect_type == WRT_InnerClipRect)        { return window->InnerClipRect; }
             else if (rect_type == WRT_WorkRect)             { return window->WorkRect; }
-            else if (rect_type == WRT_Content)              { ImVec2 min = window->InnerRect.Min - window->Scroll + window->WindowPadding; return ImRect(min, min + window->ContentSize); }
+            else if (rect_type == WRT_Content)       { ImVec2 min = window->InnerRect.Min - window->Scroll + window->WindowPadding; return ImRect(min, min + window->ContentSize); }
+            else if (rect_type == WRT_ContentIdeal)         { ImVec2 min = window->InnerRect.Min - window->Scroll + window->WindowPadding; return ImRect(min, min + window->ContentSizeIdeal); }
             else if (rect_type == WRT_ContentRegionRect)    { return window->ContentRegionRect; }
             IM_ASSERT(0);
             return ImRect();
@@ -11069,7 +11079,7 @@ void ImGui::DebugNodeWindow(ImGuiWindow* window, const char* label)
 
     ImGuiWindowFlags flags = window->Flags;
     DebugNodeDrawList(window, window->DrawList, "DrawList");
-    BulletText("Pos: (%.1f,%.1f), Size: (%.1f,%.1f), ContentSize (%.1f,%.1f)", window->Pos.x, window->Pos.y, window->Size.x, window->Size.y, window->ContentSize.x, window->ContentSize.y);
+    BulletText("Pos: (%.1f,%.1f), Size: (%.1f,%.1f), ContentSize (%.1f,%.1f) Ideal (%.1f,%.1f)", window->Pos.x, window->Pos.y, window->Size.x, window->Size.y, window->ContentSize.x, window->ContentSize.y, window->ContentSizeIdeal.x, window->ContentSizeIdeal.y);
     BulletText("Flags: 0x%08X (%s%s%s%s%s%s%s%s%s..)", flags,
         (flags & ImGuiWindowFlags_ChildWindow)  ? "Child " : "",      (flags & ImGuiWindowFlags_Tooltip)     ? "Tooltip "   : "",  (flags & ImGuiWindowFlags_Popup) ? "Popup " : "",
         (flags & ImGuiWindowFlags_Modal)        ? "Modal " : "",      (flags & ImGuiWindowFlags_ChildMenu)   ? "ChildMenu " : "",  (flags & ImGuiWindowFlags_NoSavedSettings) ? "NoSavedSettings " : "",

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               "1.80 WIP"
-#define IMGUI_VERSION_NUM           17911
+#define IMGUI_VERSION_NUM           17912
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 

imgui_internal.h

@@ -1637,7 +1637,8 @@ struct IMGUI_API ImGuiWindowTempData
     ImVec2                  CursorPos;              // Current emitting position, in absolute coordinates.
     ImVec2                  CursorPosPrevLine;
     ImVec2                  CursorStartPos;         // Initial position after Begin(), generally ~ window position + WindowPadding.
-    ImVec2                  CursorMaxPos;           // Used to implicitly calculate the size of our contents, always growing during the frame. Used to calculate window->ContentSize at the beginning of next frame
+    ImVec2                  CursorMaxPos;           // Used to implicitly calculate ContentSize at the beginning of next frame. Always growing during the frame.
+    ImVec2                  IdealMaxPos;            // Used to implicitly calculate ContentSizeIdeal.
     ImVec2                  CurrLineSize;
     ImVec2                  PrevLineSize;
     float                   CurrLineTextBaseOffset; // Baseline offset (0.0f by default on a new line, generally == style.FramePadding.y when a framed item has been added).
@@ -1695,6 +1696,7 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  Size;                               // Current size (==SizeFull or collapsed title bar size)
     ImVec2                  SizeFull;                           // Size when non collapsed
     ImVec2                  ContentSize;                        // Size of contents/scrollable client area (calculated from the extents reach of the cursor) from previous frame. Does not include window decoration or window padding.
+    ImVec2                  ContentSizeIdeal;
     ImVec2                  ContentSizeExplicit;                // Size of contents/scrollable client area explicitly request by the user via SetNextWindowContentSize().
     ImVec2                  WindowPadding;                      // Window padding at the time of Begin().
     float                   WindowRounding;                     // Window rounding at the time of Begin(). May be clamped lower to avoid rendering artifacts with title bar, menu bar etc.
@@ -2146,7 +2148,7 @@ namespace ImGui
     IMGUI_API ImGuiWindow*  FindWindowByID(ImGuiID id);
     IMGUI_API ImGuiWindow*  FindWindowByName(const char* name);
     IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
-    IMGUI_API ImVec2        CalcWindowExpectedSize(ImGuiWindow* window);
+    IMGUI_API ImVec2        CalcWindowNextAutoFitSize(ImGuiWindow* window);
     IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent);
     IMGUI_API bool          IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below);
     IMGUI_API bool          IsWindowNavFocusable(ImGuiWindow* window);

imgui_widgets.cpp

@@ -1614,7 +1614,7 @@ bool ImGui::BeginCombo(const char* label, const char* preview_value, ImGuiComboF
         if (popup_window->WasActive)
         {
             // Always override 'AutoPosLastDirection' to not leave a chance for a past value to affect us.
-            ImVec2 size_expected = CalcWindowExpectedSize(popup_window);
+            ImVec2 size_expected = CalcWindowNextAutoFitSize(popup_window);
             if (flags & ImGuiComboFlags_PopupAlignLeft)
                 popup_window->AutoPosLastDirection = ImGuiDir_Left; // "Below, Toward Left"
             else