Viewports: Internal: rename LastFrontMostStampCount -> LastFocusedStampCount. Rename ImGuiViewportFlags_Minimized -> ImGuiViewportFlags_IsMinimized

Effectively it is currently the later, but see comment "Even without focus, we assume the window becomes front-most." in UpdatePlatformWindows().
+ Moved Window field at top since it is most useful.

imgui.cpp

@@ -4956,7 +4956,7 @@ static void SetupViewportDrawData(ImGuiViewportP* viewport, ImVector<ImDrawList*
     // FIXME: Note that we however do NOT attempt to report "zero drawlist / vertices" into the ImDrawData structure.
     // This is because the work has been done already, and its wasted! We should fix that and add optimizations for
     // it earlier in the pipeline, rather than pretend to hide the data at the end of the pipeline.
-    const bool is_minimized = (viewport->Flags & ImGuiViewportFlags_Minimized) != 0;
+    const bool is_minimized = (viewport->Flags & ImGuiViewportFlags_IsMinimized) != 0;
 
     ImGuiIO& io = ImGui::GetIO();
     ImDrawData* draw_data = &viewport->DrawDataP;
@@ -6840,7 +6840,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
             window->Pos = FindBestWindowPosForPopup(window);
 
         // Late create viewport if we don't fit within our current host viewport.
-        if (window->ViewportAllowPlatformMonitorExtend >= 0 && !window->ViewportOwned && !(window->Viewport->Flags & ImGuiViewportFlags_Minimized))
+        if (window->ViewportAllowPlatformMonitorExtend >= 0 && !window->ViewportOwned && !(window->Viewport->Flags & ImGuiViewportFlags_IsMinimized))
             if (!window->Viewport->GetMainRect().Contains(window->Rect()))
             {
                 // This is based on the assumption that the DPI will be known ahead (same as the DPI of the selection done in UpdateSelectWindowViewport)
@@ -13776,7 +13776,7 @@ static bool ImGui::UpdateTryMergeWindowIntoHostViewport(ImGuiWindow* window, ImG
         return false;
     if ((viewport->Flags & ImGuiViewportFlags_CanHostOtherWindows) == 0)
         return false;
-    if ((viewport->Flags & ImGuiViewportFlags_Minimized) != 0)
+    if ((viewport->Flags & ImGuiViewportFlags_IsMinimized) != 0)
         return false;
     if (!viewport->GetMainRect().Contains(window->Rect()))
         return false;
@@ -13859,8 +13859,8 @@ ImGuiViewportP* ImGui::FindHoveredViewportFromPlatformWindowStack(const ImVec2&
     for (int n = 0; n < g.Viewports.Size; n++)
     {
         ImGuiViewportP* viewport = g.Viewports[n];
-        if (!(viewport->Flags & (ImGuiViewportFlags_NoInputs | ImGuiViewportFlags_Minimized)) && viewport->GetMainRect().Contains(mouse_platform_pos))
-            if (best_candidate == NULL || best_candidate->LastFrontMostStampCount < viewport->LastFrontMostStampCount)
+        if (!(viewport->Flags & (ImGuiViewportFlags_NoInputs | ImGuiViewportFlags_IsMinimized)) && viewport->GetMainRect().Contains(mouse_platform_pos))
+            if (best_candidate == NULL || best_candidate->LastFocusedStampCount < viewport->LastFocusedStampCount)
                 best_candidate = viewport;
     }
     return best_candidate;
@@ -13885,9 +13885,9 @@ static void ImGui::UpdateViewportsNewFrame()
             {
                 bool minimized = g.PlatformIO.Platform_GetWindowMinimized(viewport);
                 if (minimized)
-                    viewport->Flags |= ImGuiViewportFlags_Minimized;
+                    viewport->Flags |= ImGuiViewportFlags_IsMinimized;
                 else
-                    viewport->Flags &= ~ImGuiViewportFlags_Minimized;
+                    viewport->Flags &= ~ImGuiViewportFlags_IsMinimized;
             }
         }
     }
@@ -13899,7 +13899,7 @@ static void ImGui::UpdateViewportsNewFrame()
     IM_ASSERT(main_viewport->Window == NULL);
     ImVec2 main_viewport_pos = viewports_enabled ? g.PlatformIO.Platform_GetWindowPos(main_viewport) : ImVec2(0.0f, 0.0f);
     ImVec2 main_viewport_size = g.IO.DisplaySize;
-    if (viewports_enabled && (main_viewport->Flags & ImGuiViewportFlags_Minimized))
+    if (viewports_enabled && (main_viewport->Flags & ImGuiViewportFlags_IsMinimized))
     {
         main_viewport_pos = main_viewport->Pos;    // Preserve last pos/size when minimized (FIXME: We don't do the same for Size outside of the viewport path)
         main_viewport_size = main_viewport->Size;
@@ -13927,7 +13927,7 @@ static void ImGui::UpdateViewportsNewFrame()
         {
             // Update Position and Size (from Platform Window to ImGui) if requested.
             // We do it early in the frame instead of waiting for UpdatePlatformWindows() to avoid a frame of lag when moving/resizing using OS facilities.
-            if (!(viewport->Flags & ImGuiViewportFlags_Minimized) && platform_funcs_available)
+            if (!(viewport->Flags & ImGuiViewportFlags_IsMinimized) && platform_funcs_available)
             {
                 // Viewport->WorkPos and WorkSize will be updated below
                 if (viewport->PlatformRequestMove)
@@ -14088,7 +14088,7 @@ ImGuiViewportP* ImGui::AddUpdateViewport(ImGuiWindow* window, ImGuiID id, const
             viewport->Pos = pos;
         if (!viewport->PlatformRequestResize || viewport->ID == IMGUI_VIEWPORT_DEFAULT_ID)
             viewport->Size = size;
-        viewport->Flags = flags | (viewport->Flags & ImGuiViewportFlags_Minimized); // Preserve existing flags
+        viewport->Flags = flags | (viewport->Flags & ImGuiViewportFlags_IsMinimized); // Preserve existing flags
     }
     else
     {
@@ -14465,9 +14465,9 @@ void ImGui::UpdatePlatformWindows()
 
             // Even without focus, we assume the window becomes front-most.
             // This is useful for our platform z-order heuristic when io.MouseHoveredViewport is not available.
-            if (viewport->LastFrontMostStampCount != g.ViewportFrontMostStampCount)
-                viewport->LastFrontMostStampCount = ++g.ViewportFrontMostStampCount;
-            }
+            if (viewport->LastFocusedStampCount != g.ViewportFocusedStampCount)
+                viewport->LastFocusedStampCount = ++g.ViewportFocusedStampCount;
+        }
 
         // Clear request flags
         viewport->ClearRequestFlags();
@@ -14487,14 +14487,17 @@ void ImGui::UpdatePlatformWindows()
                     focused_viewport = viewport;
         }
 
-        // Store a tag so we can infer z-order easily from all our windows
-        // We compare PlatformLastFocusedViewportId so newly created viewports with _NoFocusOnAppearing flag
-        // will keep the front most stamp instead of losing it back to their parent viewport.
+        // Focused viewport has changed?
         if (focused_viewport && g.PlatformLastFocusedViewportId != focused_viewport->ID)
         {
-            if (focused_viewport->LastFrontMostStampCount != g.ViewportFrontMostStampCount)
-                focused_viewport->LastFrontMostStampCount = ++g.ViewportFrontMostStampCount;
+            // Store a tag so we can infer z-order easily from all our windows
+            // We compare PlatformLastFocusedViewportId so newly created viewports with _NoFocusOnAppearing flag
+            // will keep the front most stamp instead of losing it back to their parent viewport.
+            if (focused_viewport->LastFocusedStampCount != g.ViewportFocusedStampCount)
+                focused_viewport->LastFocusedStampCount = ++g.ViewportFocusedStampCount;
             g.PlatformLastFocusedViewportId = focused_viewport->ID;
+
+            // Focus associated dear imgui window (#6299)
             if (focused_viewport->Window != NULL)
                 FocusWindow(NavRestoreLastChildNavWindow(focused_viewport->Window));
             else
@@ -14522,7 +14525,7 @@ void ImGui::RenderPlatformWindowsDefault(void* platform_render_arg, void* render
     for (int i = 1; i < platform_io.Viewports.Size; i++)
     {
         ImGuiViewport* viewport = platform_io.Viewports[i];
-        if (viewport->Flags & ImGuiViewportFlags_Minimized)
+        if (viewport->Flags & ImGuiViewportFlags_IsMinimized)
             continue;
         if (platform_io.Platform_RenderWindow) platform_io.Platform_RenderWindow(viewport, platform_render_arg);
         if (platform_io.Renderer_RenderWindow) platform_io.Renderer_RenderWindow(viewport, renderer_render_arg);
@@ -14530,7 +14533,7 @@ void ImGui::RenderPlatformWindowsDefault(void* platform_render_arg, void* render
     for (int i = 1; i < platform_io.Viewports.Size; i++)
     {
         ImGuiViewport* viewport = platform_io.Viewports[i];
-        if (viewport->Flags & ImGuiViewportFlags_Minimized)
+        if (viewport->Flags & ImGuiViewportFlags_IsMinimized)
             continue;
         if (platform_io.Platform_SwapBuffers) platform_io.Platform_SwapBuffers(viewport, platform_render_arg);
         if (platform_io.Renderer_SwapBuffers) platform_io.Renderer_SwapBuffers(viewport, renderer_render_arg);
@@ -18736,7 +18739,7 @@ void ImGui::DebugRenderViewportThumbnail(ImDrawList* draw_list, ImGuiViewportP*
 
     ImVec2 scale = bb.GetSize() / viewport->Size;
     ImVec2 off = bb.Min - viewport->Pos * scale;
-    float alpha_mul = (viewport->Flags & ImGuiViewportFlags_Minimized) ? 0.30f : 1.00f;
+    float alpha_mul = (viewport->Flags & ImGuiViewportFlags_IsMinimized) ? 0.30f : 1.00f;
     window->DrawList->AddRectFilled(bb.Min, bb.Max, ImGui::GetColorU32(ImGuiCol_Border, alpha_mul * 0.40f));
     for (int i = 0; i != g.Windows.Size; i++)
     {
@@ -18782,11 +18785,11 @@ static void RenderViewportsThumbnails()
     ImGui::Dummy(bb_full.GetSize() * SCALE);
 }
 
-static int IMGUI_CDECL ViewportComparerByFrontMostStampCount(const void* lhs, const void* rhs)
+static int IMGUI_CDECL ViewportComparerByLastFocusedStampCount(const void* lhs, const void* rhs)
 {
     const ImGuiViewportP* a = *(const ImGuiViewportP* const*)lhs;
     const ImGuiViewportP* b = *(const ImGuiViewportP* const*)rhs;
-    return b->LastFrontMostStampCount - a->LastFrontMostStampCount;
+    return b->LastFocusedStampCount - a->LastFocusedStampCount;
 }
 
 // Draw an arbitrary US keyboard layout to visualize translated keys
@@ -19159,10 +19162,10 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             viewports.resize(g.Viewports.Size);
             memcpy(viewports.Data, g.Viewports.Data, g.Viewports.size_in_bytes());
             if (viewports.Size > 1)
-                ImQsort(viewports.Data, viewports.Size, sizeof(ImGuiViewport*), ViewportComparerByFrontMostStampCount);
+                ImQsort(viewports.Data, viewports.Size, sizeof(ImGuiViewport*), ViewportComparerByLastFocusedStampCount);
             for (ImGuiViewportP* viewport : viewports)
-                BulletText("Viewport #%d, ID: 0x%08X, FrontMostStampCount = %08d, PlatformFocused = %s, Window: \"%s\"",
-                    viewport->Idx, viewport->ID, viewport->LastFrontMostStampCount,
+                BulletText("Viewport #%d, ID: 0x%08X, LastFocused = %08d, PlatformFocused = %s, Window: \"%s\"",
+                    viewport->Idx, viewport->ID, viewport->LastFocusedStampCount,
                     (g.PlatformIO.Platform_GetWindowFocus && viewport->PlatformWindowCreated) ? (g.PlatformIO.Platform_GetWindowFocus(viewport) ? "1" : "0") : "N/A",
                     viewport->Window ? viewport->Window->Name : "N/A");
             TreePop();
@@ -19923,7 +19926,7 @@ void ImGui::DebugNodeViewport(ImGuiViewportP* viewport)
             (flags & ImGuiViewportFlags_NoInputs) ? " NoInputs" : "",
             (flags & ImGuiViewportFlags_NoRendererClear) ? " NoRendererClear" : "",
             (flags & ImGuiViewportFlags_TopMost) ? " TopMost" : "",
-            (flags & ImGuiViewportFlags_Minimized) ? " Minimized" : "",
+            (flags & ImGuiViewportFlags_IsMinimized) ? " IsMinimized" : "",
             (flags & ImGuiViewportFlags_NoAutoMerge) ? " NoAutoMerge" : "",
             (flags & ImGuiViewportFlags_CanHostOtherWindows) ? " CanHostOtherWindows" : "");
         for (int layer_i = 0; layer_i < IM_ARRAYSIZE(viewport->DrawDataBuilder.Layers); layer_i++)

imgui.h

@@ -3075,17 +3075,19 @@ enum ImGuiViewportFlags_
     ImGuiViewportFlags_None                     = 0,
     ImGuiViewportFlags_IsPlatformWindow         = 1 << 0,   // Represent a Platform Window
     ImGuiViewportFlags_IsPlatformMonitor        = 1 << 1,   // Represent a Platform Monitor (unused yet)
-    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: is created/managed by the application (rather than a dear imgui backend)
+    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: Was created/managed by the user application? (rather than our backend)
     ImGuiViewportFlags_NoDecoration             = 1 << 3,   // Platform Window: Disable platform decorations: title bar, borders, etc. (generally set all windows, but if ImGuiConfigFlags_ViewportsDecoration is set we only set this on popups/tooltips)
     ImGuiViewportFlags_NoTaskBarIcon            = 1 << 4,   // Platform Window: Disable platform task bar icon (generally set on popups/tooltips, or all windows if ImGuiConfigFlags_ViewportsNoTaskBarIcon is set)
     ImGuiViewportFlags_NoFocusOnAppearing       = 1 << 5,   // Platform Window: Don't take focus when created.
     ImGuiViewportFlags_NoFocusOnClick           = 1 << 6,   // Platform Window: Don't take focus when clicked on.
     ImGuiViewportFlags_NoInputs                 = 1 << 7,   // Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
     ImGuiViewportFlags_NoRendererClear          = 1 << 8,   // Platform Window: Renderer doesn't need to clear the framebuffer ahead (because we will fill it entirely).
-    ImGuiViewportFlags_TopMost                  = 1 << 9,   // Platform Window: Display on top (for tooltips only).
-    ImGuiViewportFlags_Minimized                = 1 << 10,  // Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
-    ImGuiViewportFlags_NoAutoMerge              = 1 << 11,  // Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
-    ImGuiViewportFlags_CanHostOtherWindows      = 1 << 12,  // Main viewport: can host multiple imgui windows (secondary viewports are associated to a single window).
+    ImGuiViewportFlags_NoAutoMerge              = 1 << 9,   // Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
+    ImGuiViewportFlags_TopMost                  = 1 << 10,  // Platform Window: Display on top (for tooltips only).
+    ImGuiViewportFlags_CanHostOtherWindows      = 1 << 11,  // Viewport can host multiple imgui windows (secondary viewports are associated to a single window). // FIXME: In practice there's still probably code making the assumption that this is always and only on the MainViewport. Will fix once we add support for "no main viewport".
+
+    // Output status flags (from Platform)
+    ImGuiViewportFlags_IsMinimized              = 1 << 12,  // Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
 };
 
 // - Currently represents the Platform Window created by the application which is hosting our Dear ImGui windows.

imgui_internal.h

@@ -1730,15 +1730,15 @@ struct ImGuiDockContext
 // Every instance of ImGuiViewport is in fact a ImGuiViewportP.
 struct ImGuiViewportP : public ImGuiViewport
 {
+    ImGuiWindow*        Window;                 // Set when the viewport is owned by a window (and ImGuiViewportFlags_CanHostOtherWindows is NOT set)
     int                 Idx;
     int                 LastFrameActive;        // Last frame number this viewport was activated by a window
-    int                 LastFrontMostStampCount;// Last stamp number from when a window hosted by this viewport was made front-most (by comparing this value between two viewport we have an implicit viewport z-order
+    int                 LastFocusedStampCount;  // Last stamp number from when a window hosted by this viewport was focused (by comparing this value between two viewport we have an implicit viewport z-order we use as fallback)
     ImGuiID             LastNameHash;
     ImVec2              LastPos;
     float               Alpha;                  // Window opacity (when dragging dockable windows/viewports we make them transparent)
     float               LastAlpha;
     short               PlatformMonitor;
-    ImGuiWindow*        Window;                 // Set when the viewport is owned by a window (and ImGuiViewportFlags_CanHostOtherWindows is NOT set)
     int                 DrawListsLastFrame[2];  // Last frame number the background (0) and foreground (1) draw lists were used
     ImDrawList*         DrawLists[2];           // Convenience background (0) and foreground (1) draw lists. We use them to draw software mouser cursor when io.MouseDrawCursor is set and to draw most debug overlays.
     ImDrawData          DrawDataP;
@@ -1751,7 +1751,7 @@ struct ImGuiViewportP : public ImGuiViewport
     ImVec2              BuildWorkOffsetMin;     // Work Area: Offset being built during current frame. Generally >= 0.0f.
     ImVec2              BuildWorkOffsetMax;     // Work Area: Offset being built during current frame. Generally <= 0.0f.
 
-    ImGuiViewportP()                    { Idx = -1; LastFrameActive = DrawListsLastFrame[0] = DrawListsLastFrame[1] = LastFrontMostStampCount = -1; LastNameHash = 0; Alpha = LastAlpha = 1.0f; PlatformMonitor = -1; Window = NULL; DrawLists[0] = DrawLists[1] = NULL; LastPlatformPos = LastPlatformSize = LastRendererSize = ImVec2(FLT_MAX, FLT_MAX); }
+    ImGuiViewportP()                    { Window = NULL; Idx = -1; LastFrameActive = DrawListsLastFrame[0] = DrawListsLastFrame[1] = LastFocusedStampCount = -1; LastNameHash = 0; Alpha = LastAlpha = 1.0f; PlatformMonitor = -1; Window = NULL; DrawLists[0] = DrawLists[1] = NULL; LastPlatformPos = LastPlatformSize = LastRendererSize = ImVec2(FLT_MAX, FLT_MAX); }
     ~ImGuiViewportP()                   { if (DrawLists[0]) IM_DELETE(DrawLists[0]); if (DrawLists[1]) IM_DELETE(DrawLists[1]); }
     void    ClearRequestFlags()         { PlatformRequestClose = PlatformRequestMove = PlatformRequestResize = false; }
 
@@ -2026,7 +2026,7 @@ struct ImGuiContext
     ImGuiViewportP*         MouseLastHoveredViewport;           // Last known viewport that was hovered by mouse (even if we are not hovering any viewport any more) + honoring the _NoInputs flag.
     ImGuiID                 PlatformLastFocusedViewportId;
     ImGuiPlatformMonitor    FallbackMonitor;                    // Virtual monitor used as fallback if backend doesn't provide monitor information.
-    int                     ViewportFrontMostStampCount;        // Every time the front-most window changes, we stamp its viewport with an incrementing counter
+    int                     ViewportFocusedStampCount;          // Every time the front-most window changes, we stamp its viewport with an incrementing counter
 
     // Gamepad/keyboard Navigation
     ImGuiWindow*            NavWindow;                          // Focused window for navigation. Could be called 'FocusedWindow'
@@ -2288,7 +2288,7 @@ struct ImGuiContext
         CurrentViewport = NULL;
         MouseViewport = MouseLastHoveredViewport = NULL;
         PlatformLastFocusedViewportId = 0;
-        ViewportFrontMostStampCount = 0;
+        ViewportFocusedStampCount = 0;
 
         NavWindow = NULL;
         NavId = NavFocusScopeId = NavActivateId = NavActivateDownId = NavActivatePressedId = 0;