Internals: Moved code out of SliderBehaviorT to reduce code bloat and also because caller may have use for the grab_bb for styling purposes.

imgui.cpp

@@ -921,7 +921,7 @@ template<typename TYPE, typename SIGNEDTYPE, typename FLOATTYPE>
 static bool             DragBehaviorT(ImGuiDataType data_type, TYPE* v, float v_speed, const TYPE v_min, const TYPE v_max, const char* format, float power);
 
 template<typename TYPE, typename SIGNEDTYPE, typename FLOATTYPE>
-static bool             SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, TYPE* v, const TYPE v_min, const TYPE v_max, const char* format, float power, ImGuiSliderFlags flags);
+static bool             SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, TYPE* v, const TYPE v_min, const TYPE v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb);
 }
 
 //-----------------------------------------------------------------------------
@@ -9346,10 +9346,9 @@ static inline float SliderBehaviorCalcRatioFromValue(ImGuiDataType data_type, TY
 
 // FIXME: Move some of the code into SliderBehavior(). Current responsability is larger than what the equivalent DragBehaviorT<> does, we also do some rendering, etc.
 template<typename TYPE, typename SIGNEDTYPE, typename FLOATTYPE>
-static bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, TYPE* v, const TYPE v_min, const TYPE v_max, const char* format, float power, ImGuiSliderFlags flags)
+static bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, TYPE* v, const TYPE v_min, const TYPE v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     const ImGuiStyle& style = g.Style;
 
     const bool is_horizontal = (flags & ImGuiSliderFlags_Vertical) == 0;
@@ -9496,17 +9495,15 @@ static bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType d
         }
     }
 
-    // Draw
+    // Output grab position so it can be displayed by the caller
     float grab_t = SliderBehaviorCalcRatioFromValue<TYPE,FLOATTYPE>(data_type, *v, v_min, v_max, power, linear_zero_pos);
     if (!is_horizontal)
         grab_t = 1.0f - grab_t;
     const float grab_pos = ImLerp(slider_usable_pos_min, slider_usable_pos_max, grab_t);
-    ImRect grab_bb;
     if (is_horizontal)
-        grab_bb = ImRect(grab_pos - grab_sz*0.5f, bb.Min.y + grab_padding, grab_pos + grab_sz*0.5f, bb.Max.y - grab_padding);
+        *out_grab_bb = ImRect(grab_pos - grab_sz*0.5f, bb.Min.y + grab_padding, grab_pos + grab_sz*0.5f, bb.Max.y - grab_padding);
     else
-        grab_bb = ImRect(bb.Min.x + grab_padding, grab_pos - grab_sz*0.5f, bb.Max.x - grab_padding, grab_pos + grab_sz*0.5f);
-    window->DrawList->AddRectFilled(grab_bb.Min, grab_bb.Max, GetColorU32(g.ActiveId == id ? ImGuiCol_SliderGrabActive : ImGuiCol_SliderGrab), style.GrabRounding);
+        *out_grab_bb = ImRect(bb.Min.x + grab_padding, grab_pos - grab_sz*0.5f, bb.Max.x - grab_padding, grab_pos + grab_sz*0.5f);
 
     return value_changed;
 }
@@ -9514,34 +9511,28 @@ static bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType d
 // For 32-bits and larger types, slider bounds are limited to half the natural type range.
 // So e.g. an integer Slider between INT_MAX-10 and INT_MAX will fail, but an integer Slider between INT_MAX/2-10 and INT_MAX/2 will be ok.
 // It would be possible to lift that limitation with some work but it doesn't seem to be worth it for sliders.
-bool ImGui::SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* v, const void* v_min, const void* v_max, const char* format, float power, ImGuiSliderFlags flags)
+bool ImGui::SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* v, const void* v_min, const void* v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb)
 {
-    // Draw frame
-    ImGuiContext& g = *GImGui;
-    const ImU32 frame_col = GetColorU32(g.ActiveId == id ? ImGuiCol_FrameBgActive : g.HoveredId == id ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg);
-    RenderNavHighlight(bb, id);
-    RenderFrame(bb.Min, bb.Max, frame_col, true, g.Style.FrameRounding);
-
     switch (data_type)
     {
     case ImGuiDataType_S32:
         IM_ASSERT(*(const ImS32*)v_min >= IM_S32_MIN/2 && *(const ImS32*)v_max <= IM_S32_MAX/2);
-        return SliderBehaviorT<ImS32, ImS32, float >(bb, id, data_type, (ImS32*)v,  *(const ImS32*)v_min,  *(const ImS32*)v_max,  format, power, flags);
+        return SliderBehaviorT<ImS32, ImS32, float >(bb, id, data_type, (ImS32*)v,  *(const ImS32*)v_min,  *(const ImS32*)v_max,  format, power, flags, out_grab_bb);
     case ImGuiDataType_U32:
         IM_ASSERT(*(const ImU32*)v_min <= IM_U32_MAX/2);
-        return SliderBehaviorT<ImU32, ImS32, float >(bb, id, data_type, (ImU32*)v,  *(const ImU32*)v_min,  *(const ImU32*)v_max,  format, power, flags);
+        return SliderBehaviorT<ImU32, ImS32, float >(bb, id, data_type, (ImU32*)v,  *(const ImU32*)v_min,  *(const ImU32*)v_max,  format, power, flags, out_grab_bb);
     case ImGuiDataType_S64:
         IM_ASSERT(*(const ImS64*)v_min >= IM_S64_MIN/2 && *(const ImS64*)v_max <= IM_S64_MAX/2);
-        return SliderBehaviorT<ImS64, ImS64, double>(bb, id, data_type, (ImS64*)v,  *(const ImS64*)v_min,  *(const ImS64*)v_max,  format, power, flags);
+        return SliderBehaviorT<ImS64, ImS64, double>(bb, id, data_type, (ImS64*)v,  *(const ImS64*)v_min,  *(const ImS64*)v_max,  format, power, flags, out_grab_bb);
     case ImGuiDataType_U64:
         IM_ASSERT(*(const ImU64*)v_min <= IM_U64_MAX/2);
-        return SliderBehaviorT<ImU64, ImS64, double>(bb, id, data_type, (ImU64*)v,  *(const ImU64*)v_min,  *(const ImU64*)v_max,  format, power, flags);
+        return SliderBehaviorT<ImU64, ImS64, double>(bb, id, data_type, (ImU64*)v,  *(const ImU64*)v_min,  *(const ImU64*)v_max,  format, power, flags, out_grab_bb);
     case ImGuiDataType_Float:
         IM_ASSERT(*(const float*)v_min >= -FLT_MAX/2.0f && *(const float*)v_max <= FLT_MAX/2.0f);
-        return SliderBehaviorT<float, float, float >(bb, id, data_type, (float*)v,  *(const float*)v_min,  *(const float*)v_max,  format, power, flags);
+        return SliderBehaviorT<float, float, float >(bb, id, data_type, (float*)v,  *(const float*)v_min,  *(const float*)v_max,  format, power, flags, out_grab_bb);
     case ImGuiDataType_Double:
         IM_ASSERT(*(const double*)v_min >= -DBL_MAX/2.0f && *(const double*)v_max <= DBL_MAX/2.0f);
-        return SliderBehaviorT<double,double,double>(bb, id, data_type, (double*)v, *(const double*)v_min, *(const double*)v_max, format, power, flags);
+        return SliderBehaviorT<double,double,double>(bb, id, data_type, (double*)v, *(const double*)v_min, *(const double*)v_max, format, power, flags, out_grab_bb);
     case ImGuiDataType_COUNT: break;
     }
     IM_ASSERT(0);
@@ -9621,12 +9612,22 @@ bool ImGui::SliderScalar(const char* label, ImGuiDataType data_type, void* v, co
     if (start_text_input || (g.ActiveId == id && g.ScalarAsInputTextId == id))
         return InputScalarAsWidgetReplacement(frame_bb, id, label, data_type, v, format);
 
-    // Actual slider behavior + render grab
     ItemSize(total_bb, style.FramePadding.y);
-    const bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power);
+
+    // Draw frame
+    const ImU32 frame_col = GetColorU32(g.ActiveId == id ? ImGuiCol_FrameBgActive : g.HoveredId == id ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg);
+    RenderNavHighlight(frame_bb, id);
+    RenderFrame(frame_bb.Min, frame_bb.Max, frame_col, true, g.Style.FrameRounding);
+
+    // Slider behavior
+    ImRect grab_bb;
+    const bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power, ImGuiSliderFlags_None, &grab_bb);
     if (value_changed)
         MarkItemValueChanged(id);
 
+    // Render grab
+    window->DrawList->AddRectFilled(grab_bb.Min, grab_bb.Max, GetColorU32(g.ActiveId == id ? ImGuiCol_SliderGrabActive : ImGuiCol_SliderGrab), style.GrabRounding);
+
     // Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
     char value_buf[64];
     const char* value_buf_end = value_buf + DataTypeFormatString(value_buf, IM_ARRAYSIZE(value_buf), data_type, v, format);
@@ -9678,11 +9679,21 @@ bool ImGui::VSliderScalar(const char* label, const ImVec2& size, ImGuiDataType d
         g.ActiveIdAllowNavDirFlags = (1 << ImGuiDir_Left) | (1 << ImGuiDir_Right);
     }
 
-    // Actual slider behavior + render grab
-    const bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power, ImGuiSliderFlags_Vertical);
+
+    // Draw frame
+    const ImU32 frame_col = GetColorU32(g.ActiveId == id ? ImGuiCol_FrameBgActive : g.HoveredId == id ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg);
+    RenderNavHighlight(frame_bb, id);
+    RenderFrame(frame_bb.Min, frame_bb.Max, frame_col, true, g.Style.FrameRounding);
+
+    // Slider behavior
+    ImRect grab_bb;
+    const bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power, ImGuiSliderFlags_Vertical, &grab_bb);
     if (value_changed)
         MarkItemValueChanged(id);
 
+    // Render grab
+    window->DrawList->AddRectFilled(grab_bb.Min, grab_bb.Max, GetColorU32(g.ActiveId == id ? ImGuiCol_SliderGrabActive : ImGuiCol_SliderGrab), style.GrabRounding);
+
     // Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
     // For the vertical slider we allow centered text to overlap the frame padding
     char value_buf[64];

imgui_internal.h

@@ -1198,7 +1198,7 @@ namespace ImGui
     // Widgets low-level behaviors
     IMGUI_API bool          ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags = 0);
     IMGUI_API bool          DragBehavior(ImGuiID id, ImGuiDataType data_type, void* v, float v_speed, const void* v_min, const void* v_max, const char* format, float power);
-    IMGUI_API bool          SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* v, const void* v_min, const void* v_max, const char* format, float power, ImGuiSliderFlags flags = 0);
+    IMGUI_API bool          SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* v, const void* v_min, const void* v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb);
     IMGUI_API bool          SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend = 0.0f, float hover_visibility_delay = 0.0f);
     IMGUI_API bool          TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* label, const char* label_end = NULL);
     IMGUI_API bool          TreeNodeBehaviorIsOpen(ImGuiID id, ImGuiTreeNodeFlags flags = 0);                     // Consume previous SetNextTreeNodeOpened() data, if any. May return true when logging