SetNextWindowSizeConstraints() clarified parameters, fixed comments. (#…

…1139, #3186, #3270)
ocornut · Nov 13, 2023 · fe65446 · fe65446
1 parent 454f36d
commit fe65446
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Showing 3 changed files with 16 additions and 10 deletions.
diff --git a/imgui.cpp b/imgui.cpp
@@ -5713,7 +5713,7 @@ static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, const ImVec2& s
     ImVec2 new_size = size_desired;
     if (g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasSizeConstraint)
     {
-        // Using -1,-1 on either X/Y axis to preserve the current size.
+        // See comments in SetNextWindowSizeConstraints() for details about setting size_min an size_max.
         ImRect cr = g.NextWindowData.SizeConstraintRect;
         new_size.x = (cr.Min.x >= 0 && cr.Max.x >= 0) ? ImClamp(new_size.x, cr.Min.x, cr.Max.x) : window->SizeFull.x;
         new_size.y = (cr.Min.y >= 0 && cr.Max.y >= 0) ? ImClamp(new_size.y, cr.Min.y, cr.Max.y) : window->SizeFull.y;
@@ -7719,6 +7719,10 @@ void ImGui::SetNextWindowSize(const ImVec2& size, ImGuiCond cond)
     g.NextWindowData.SizeCond = cond ? cond : ImGuiCond_Always;
 }
 
+// For each axis:
+// - Use 0.0f as min or FLT_MAX as max if you don't want limits, e.g. size_min = (500.0f, 0.0f), size_max = (FLT_MAX, FLT_MAX) sets a minimum width.
+// - Use -1 for both min and max of same axis to preserve current size which itself is a constraint.
+// - See "Demo->Examples->Constrained-resizing window" for examples.
 void ImGui::SetNextWindowSizeConstraints(const ImVec2& size_min, const ImVec2& size_max, ImGuiSizeCallback custom_callback, void* custom_callback_user_data)
 {
     ImGuiContext& g = *GImGui;

diff --git a/imgui.h b/imgui.h
@@ -373,7 +373,7 @@ namespace ImGui
     // - Prefer using SetNextXXX functions (before Begin) rather that SetXXX functions (after Begin).
     IMGUI_API void          SetNextWindowPos(const ImVec2& pos, ImGuiCond cond = 0, const ImVec2& pivot = ImVec2(0, 0)); // set next window position. call before Begin(). use pivot=(0.5f,0.5f) to center on given point, etc.
     IMGUI_API void          SetNextWindowSize(const ImVec2& size, ImGuiCond cond = 0);                  // set next window size. set axis to 0.0f to force an auto-fit on this axis. call before Begin()
-    IMGUI_API void          SetNextWindowSizeConstraints(const ImVec2& size_min, const ImVec2& size_max, ImGuiSizeCallback custom_callback = NULL, void* custom_callback_data = NULL); // set next window size limits. use -1,-1 on either X/Y axis to preserve the current size. Sizes will be rounded down. Use callback to apply non-trivial programmatic constraints.
+    IMGUI_API void          SetNextWindowSizeConstraints(const ImVec2& size_min, const ImVec2& size_max, ImGuiSizeCallback custom_callback = NULL, void* custom_callback_data = NULL); // set next window size limits. use 0.0f or FLT_MAX if you don't want limits. Use -1 for both min and max of same axis to preserve current size (which itself is a constraint). Use callback to apply non-trivial programmatic constraints.
     IMGUI_API void          SetNextWindowContentSize(const ImVec2& size);                               // set next window content size (~ scrollable client area, which enforce the range of scrollbars). Not including window decorations (title bar, menu bar, etc.) nor WindowPadding. set an axis to 0.0f to leave it automatic. call before Begin()
     IMGUI_API void          SetNextWindowCollapsed(bool collapsed, ImGuiCond cond = 0);                 // set next window collapsed state. call before Begin()
     IMGUI_API void          SetNextWindowFocus();                                                       // set next window to be focused / top-most. call before Begin()

diff --git a/imgui_demo.cpp b/imgui_demo.cpp
@@ -7683,9 +7683,10 @@ static void ShowExampleAppConstrainedResize(bool* p_open)
     {
         "Between 100x100 and 500x500",
         "At least 100x100",
-        "Resize vertical only",
-        "Resize horizontal only",
+        "Resize vertical + lock current width",
+        "Resize horizontal + lock current height",
         "Width Between 400 and 500",
+        "Height at least 400",
         "Custom: Aspect Ratio 16:9",
         "Custom: Always Square",
         "Custom: Fixed Steps (100)",
@@ -7694,20 +7695,21 @@ static void ShowExampleAppConstrainedResize(bool* p_open)
     // Options
     static bool auto_resize = false;
     static bool window_padding = true;
-    static int type = 5; // Aspect Ratio
+    static int type = 6; // Aspect Ratio
     static int display_lines = 10;
 
     // Submit constraint
     float aspect_ratio = 16.0f / 9.0f;
     float fixed_step = 100.0f;
     if (type == 0) ImGui::SetNextWindowSizeConstraints(ImVec2(100, 100), ImVec2(500, 500));         // Between 100x100 and 500x500
     if (type == 1) ImGui::SetNextWindowSizeConstraints(ImVec2(100, 100), ImVec2(FLT_MAX, FLT_MAX)); // Width > 100, Height > 100
-    if (type == 2) ImGui::SetNextWindowSizeConstraints(ImVec2(-1, 0),    ImVec2(-1, FLT_MAX));      // Vertical only
-    if (type == 3) ImGui::SetNextWindowSizeConstraints(ImVec2(0, -1),    ImVec2(FLT_MAX, -1));      // Horizontal only
+    if (type == 2) ImGui::SetNextWindowSizeConstraints(ImVec2(-1, 0),    ImVec2(-1, FLT_MAX));      // Resize vertical + lock current width
+    if (type == 3) ImGui::SetNextWindowSizeConstraints(ImVec2(0, -1),    ImVec2(FLT_MAX, -1));      // Resize horizontal + lock current height
     if (type == 4) ImGui::SetNextWindowSizeConstraints(ImVec2(400, -1),  ImVec2(500, -1));          // Width Between and 400 and 500
-    if (type == 5) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::AspectRatio, (void*)&aspect_ratio);   // Aspect ratio
-    if (type == 6) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::Square);                              // Always Square
-    if (type == 7) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::Step, (void*)&fixed_step);            // Fixed Step
+    if (type == 5) ImGui::SetNextWindowSizeConstraints(ImVec2(-1, 500),  ImVec2(-1, FLT_MAX));      // Height at least 400
+    if (type == 6) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::AspectRatio, (void*)&aspect_ratio);   // Aspect ratio
+    if (type == 7) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::Square);                              // Always Square
+    if (type == 8) ImGui::SetNextWindowSizeConstraints(ImVec2(0, 0),     ImVec2(FLT_MAX, FLT_MAX), CustomConstraints::Step, (void*)&fixed_step);            // Fixed Step
 
     // Submit window
     if (!window_padding)