Window: Fixed resizing from upper border when io.ConfigWindowsMoveFromTitleBarOnly is set. (#6390)

docs/CHANGELOG.txt

@@ -50,6 +50,7 @@ Breaking changes:
 
 Other changes:
 
+- Window: Fixed resizing from upper border when io.ConfigWindowsMoveFromTitleBarOnly is set. (#6390)
 - Tables: Fixed a small miscalculation in TableHeader() leading to an empty tooltip
   showing when a sorting column has no visible name. (#6342) [@lukaasm]
 - Tables: Fixed command merging when compiling with VS2013 (one array on stack was not

imgui.cpp

@@ -5729,6 +5729,11 @@ static bool ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& s
     const float grip_hover_inner_size = IM_FLOOR(grip_draw_size * 0.75f);
     const float grip_hover_outer_size = g.IO.ConfigWindowsResizeFromEdges ? WINDOWS_HOVER_PADDING : 0.0f;
 
+    ImRect clamp_rect = visibility_rect;
+    const bool window_move_from_title_bar = g.IO.ConfigWindowsMoveFromTitleBarOnly && !(window->Flags & ImGuiWindowFlags_NoTitleBar);
+    if (window_move_from_title_bar)
+        clamp_rect.Min.y -= window->TitleBarHeight();
+
     ImVec2 pos_target(FLT_MAX, FLT_MAX);
     ImVec2 size_target(FLT_MAX, FLT_MAX);
 
@@ -5765,8 +5770,8 @@ static bool ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& s
         {
             // Resize from any of the four corners
             // We don't use an incremental MouseDelta but rather compute an absolute target size based on mouse position
-            ImVec2 clamp_min = ImVec2(def.CornerPosN.x == 1.0f ? visibility_rect.Min.x : -FLT_MAX, def.CornerPosN.y == 1.0f ? visibility_rect.Min.y : -FLT_MAX);
+            ImVec2 clamp_min = ImVec2(def.CornerPosN.x == 1.0f ? clamp_rect.Min.x : -FLT_MAX, (def.CornerPosN.y == 1.0f || (def.CornerPosN.y == 0.0f && window_move_from_title_bar)) ? clamp_rect.Min.y : -FLT_MAX);
-            ImVec2 clamp_max = ImVec2(def.CornerPosN.x == 0.0f ? visibility_rect.Max.x : +FLT_MAX, def.CornerPosN.y == 0.0f ? visibility_rect.Max.y : +FLT_MAX);
+            ImVec2 clamp_max = ImVec2(def.CornerPosN.x == 0.0f ? clamp_rect.Max.x : +FLT_MAX, def.CornerPosN.y == 0.0f ? clamp_rect.Max.y : +FLT_MAX);
             ImVec2 corner_target = g.IO.MousePos - g.ActiveIdClickOffset + ImLerp(def.InnerDir * grip_hover_outer_size, def.InnerDir * -grip_hover_inner_size, def.CornerPosN); // Corner of the window corresponding to our corner grip
             corner_target = ImClamp(corner_target, clamp_min, clamp_max);
             CalcResizePosSizeFromAnyCorner(window, corner_target, def.CornerPosN, &pos_target, &size_target);
@@ -5795,8 +5800,8 @@ static bool ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& s
         }
         if (held)
         {
-            ImVec2 clamp_min(border_n == ImGuiDir_Right ? visibility_rect.Min.x : -FLT_MAX, border_n == ImGuiDir_Down ? visibility_rect.Min.y : -FLT_MAX);
+            ImVec2 clamp_min(border_n == ImGuiDir_Right ? clamp_rect.Min.x : -FLT_MAX, border_n == ImGuiDir_Down || (border_n == ImGuiDir_Up && window_move_from_title_bar) ? clamp_rect.Min.y : -FLT_MAX);
-            ImVec2 clamp_max(border_n == ImGuiDir_Left  ? visibility_rect.Max.x : +FLT_MAX, border_n == ImGuiDir_Up   ? visibility_rect.Max.y : +FLT_MAX);
+            ImVec2 clamp_max(border_n == ImGuiDir_Left ? clamp_rect.Max.x : +FLT_MAX, border_n == ImGuiDir_Up ? clamp_rect.Max.y : +FLT_MAX);
             ImVec2 border_target = window->Pos;
             border_target[axis] = g.IO.MousePos[axis] - g.ActiveIdClickOffset[axis] + WINDOWS_HOVER_PADDING;
             border_target = ImClamp(border_target, clamp_min, clamp_max);
@@ -5823,7 +5828,7 @@ static bool ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& s
             const float NAV_RESIZE_SPEED = 600.0f;
             const float resize_step = NAV_RESIZE_SPEED * g.IO.DeltaTime * ImMin(g.IO.DisplayFramebufferScale.x, g.IO.DisplayFramebufferScale.y);
             g.NavWindowingAccumDeltaSize += nav_resize_dir * resize_step;
-            g.NavWindowingAccumDeltaSize = ImMax(g.NavWindowingAccumDeltaSize, visibility_rect.Min - window->Pos - window->Size); // We need Pos+Size >= visibility_rect.Min, so Size >= visibility_rect.Min - Pos, so size_delta >= visibility_rect.Min - window->Pos - window->Size
+            g.NavWindowingAccumDeltaSize = ImMax(g.NavWindowingAccumDeltaSize, clamp_rect.Min - window->Pos - window->Size); // We need Pos+Size >= clmap_rect.Min, so Size >= clmap_rect.Min - Pos, so size_delta >= clmap_rect.Min - window->Pos - window->Size
             g.NavWindowingToggleLayer = false;
             g.NavDisableMouseHover = true;
             resize_grip_col[0] = GetColorU32(ImGuiCol_ResizeGripActive);

imgui.h

@@ -23,7 +23,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.89.6 WIP"
-#define IMGUI_VERSION_NUM   18958
+#define IMGUI_VERSION_NUM   18959
 #define IMGUI_HAS_TABLE
 
 /*