Internals: InputScalarEx: Tweak internals so there is a fast path for the simple case.

(in particular because it makes it clear what the extra code is for, so people tempted to create their own InputText data transform/handler understand how little is actually needed)

imgui.cpp

@@ -10578,13 +10578,6 @@ bool ImGui::InputScalarEx(const char* label, ImGuiDataType data_type, void* data
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImVec2 label_size = CalcTextSize(label, NULL, true);
-    const ImVec2 button_size = ImVec2(GetFrameHeight(), GetFrameHeight());
-
-    BeginGroup();
-    PushID(label);
-    if (step_ptr)
-        PushItemWidth(ImMax(1.0f, CalcItemWidth() - (button_size.x + style.ItemInnerSpacing.x)*2));
 
     char buf[64];
     DataTypeFormatString(buf, IM_ARRAYSIZE(buf), data_type, data_ptr, scalar_format);
@@ -10593,35 +10586,42 @@ bool ImGui::InputScalarEx(const char* label, ImGuiDataType data_type, void* data
     if ((extra_flags & (ImGuiInputTextFlags_CharsHexadecimal | ImGuiInputTextFlags_CharsScientific)) == 0)
         extra_flags |= ImGuiInputTextFlags_CharsDecimal;
     extra_flags |= ImGuiInputTextFlags_AutoSelectAll;
-    if (InputText("", buf, IM_ARRAYSIZE(buf), extra_flags)) // PushId(label) + "" gives us the expected ID from outside point of view
-        value_changed = DataTypeApplyOpFromText(buf, GImGui->InputTextState.InitialText.begin(), data_type, data_ptr, scalar_format);
 
-    // Step buttons
     if (step_ptr)
     {
+        const float button_size = GetFrameHeight();
+
+        BeginGroup(); // The only purpose of the group here is to allow the caller to query item data e.g. IsItemActive()
+        PushID(label);
+        PushItemWidth(ImMax(1.0f, CalcItemWidth() - (button_size + style.ItemInnerSpacing.x) * 2));
+        if (InputText("", buf, IM_ARRAYSIZE(buf), extra_flags)) // PushId(label) + "" gives us the expected ID from outside point of view
+            value_changed = DataTypeApplyOpFromText(buf, g.InputTextState.InitialText.Data, data_type, data_ptr, scalar_format);
         PopItemWidth();
+
+        // Step buttons
         SameLine(0, style.ItemInnerSpacing.x);
-        if (ButtonEx("-", button_size, ImGuiButtonFlags_Repeat | ImGuiButtonFlags_DontClosePopups))
+        if (ButtonEx("-", ImVec2(button_size, button_size), ImGuiButtonFlags_Repeat | ImGuiButtonFlags_DontClosePopups))
         {
             DataTypeApplyOp(data_type, '-', data_ptr, data_ptr, g.IO.KeyCtrl && step_fast_ptr ? step_fast_ptr : step_ptr);
             value_changed = true;
         }
         SameLine(0, style.ItemInnerSpacing.x);
-        if (ButtonEx("+", button_size, ImGuiButtonFlags_Repeat | ImGuiButtonFlags_DontClosePopups))
+        if (ButtonEx("+", ImVec2(button_size, button_size), ImGuiButtonFlags_Repeat | ImGuiButtonFlags_DontClosePopups))
         {
             DataTypeApplyOp(data_type, '+', data_ptr, data_ptr, g.IO.KeyCtrl && step_fast_ptr ? step_fast_ptr : step_ptr);
             value_changed = true;
         }
-    }
-    PopID();
+        SameLine(0, style.ItemInnerSpacing.x);
+        TextUnformatted(label, FindRenderedTextEnd(label));
 
-    if (label_size.x > 0)
+        PopID();
+        EndGroup();
+    }
+    else
     {
-        SameLine(0, style.ItemInnerSpacing.x);
-        RenderText(ImVec2(window->DC.CursorPos.x, window->DC.CursorPos.y + style.FramePadding.y), label);
-        ItemSize(label_size, style.FramePadding.y);
+        if (InputText(label, buf, IM_ARRAYSIZE(buf), extra_flags))
+            value_changed = DataTypeApplyOpFromText(buf, g.InputTextState.InitialText.Data, data_type, data_ptr, scalar_format);
     }
-    EndGroup();
 
     return value_changed;
 }