Added IsItemDeactivatedAfterChange() if the last item was active previously, isn't anymore, and during its active state modified a value. Note that you may still get false positive. (#820, #956, #1875)

CHANGELOG.txt

@@ -63,7 +63,9 @@ Other Changes:
    - Each example still has its own main.cpp which you may refer you to understand how to initialize and glue everything together.
    - Some frameworks (such as the Allegro, Marmalade) handle both the "platform" and "rendering" part, and your custom engine may as well.
    - Read examples/README.txt for details.
- - Added IsItemDeactivated() to query if the last item was active previously but isn't anymore. Useful for Undo/Redo patterns. (#820, #956, #1875)
+ - Added IsItemDeactivated() to query if the last item was active previously and isn't anymore. Useful for Undo/Redo patterns. (#820, #956, #1875)
+ - Added IsItemDeactivatedAfterChange() if the last item was active previously, isn't anymore, and during its active state modified a value. 
+   Note that you may still get false positive (e.g. drag value and while holding return on the same value). (#820, #956, #1875)
  - Nav: Added support for PageUp/PageDown (explorer-style: first aim at bottom/top most item, when scroll a page worth of contents). (#787)
  - Nav: To keep the navigated item in view we also attempt to scroll the parent window as well as the current window. (#787)
  - TreeNode: Fixed nodes with ImGuiTreeNodeFlags_Leaf flag always returning true which was meaningless.

imgui.cpp

@@ -2182,6 +2182,7 @@ void ImGui::SetActiveID(ImGuiID id, ImGuiWindow* window)
     if (g.ActiveIdIsJustActivated)
     {
         g.ActiveIdTimer = 0.0f;
+        g.ActiveIdValueChanged = false;
         if (id != 0)
         {
             g.LastActiveId = id;
@@ -2249,6 +2250,15 @@ void ImGui::KeepAliveID(ImGuiID id)
         g.ActiveIdPreviousFrameIsAlive = true;
 }
 
+void ImGui::MarkItemValueChanged(ImGuiID id)
+{
+    // This marking is solely to be able to provide info for IsItemDeactivatedAfterChange().
+    // ActiveId might have been released by the time we call this (as in the typical press/release button behavior) but still need need to fill the data.
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(g.ActiveId == id || g.ActiveId == 0);
+    g.ActiveIdValueChanged = true;
+}
+
 static inline bool IsWindowContentHoverable(ImGuiWindow* window, ImGuiHoveredFlags flags)
 {
     // An active popup disable hovering on other windows (apart from its own children)
@@ -3716,6 +3726,7 @@ void ImGui::NewFrame()
     g.LastActiveIdTimer += g.IO.DeltaTime;
     g.ActiveIdPreviousFrame = g.ActiveId;
     g.ActiveIdPreviousFrameWindow = g.ActiveIdWindow;
+    g.ActiveIdPreviousFrameValueChanged = g.ActiveIdValueChanged;
     g.ActiveIdIsAlive = g.ActiveIdPreviousFrameIsAlive = false;
     g.ActiveIdIsJustActivated = false;
     if (g.ScalarAsInputTextId && g.ActiveId != g.ScalarAsInputTextId)
@@ -4982,6 +4993,12 @@ bool ImGui::IsItemDeactivated()
     return (g.ActiveIdPreviousFrame == window->DC.LastItemId && g.ActiveIdPreviousFrame != 0 && g.ActiveId != window->DC.LastItemId);
 }
 
+bool ImGui::IsItemDeactivatedAfterChange()
+{
+    ImGuiContext& g = *GImGui;
+    return IsItemDeactivated() && (g.ActiveIdPreviousFrameValueChanged || (g.ActiveId == 0 && g.ActiveIdValueChanged));
+}
+
 bool ImGui::IsItemFocused()
 {
     ImGuiContext& g = *GImGui;
@@ -8022,6 +8039,8 @@ bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags
         flags |= ImGuiButtonFlags_Repeat;
     bool hovered, held;
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
+    if (pressed)
+        MarkItemValueChanged(id);
 
     // Render
     const ImU32 col = GetColorU32((hovered && held) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
@@ -9327,6 +9346,8 @@ bool ImGui::SliderScalar(const char* label, ImGuiDataType data_type, void* v, co
     // 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);
+    if (value_changed)
+        MarkItemValueChanged(id);
 
     // Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
     char value_buf[64];
@@ -9380,7 +9401,9 @@ bool ImGui::VSliderScalar(const char* label, const ImVec2& size, ImGuiDataType d
     }
 
     // Actual slider behavior + render grab
-    bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power, ImGuiSliderFlags_Vertical);
+    const bool value_changed = SliderBehavior(frame_bb, id, data_type, v, v_min, v_max, format, power, ImGuiSliderFlags_Vertical);
+    if (value_changed)
+        MarkItemValueChanged(id);
 
     // 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
@@ -9657,6 +9680,8 @@ bool ImGui::DragScalar(const char* label, ImGuiDataType data_type, void* v, floa
     // Actual drag behavior
     ItemSize(total_bb, style.FramePadding.y);
     const bool value_changed = DragBehavior(id, data_type, v, v_speed, v_min, v_max, format, power);
+    if (value_changed)
+        MarkItemValueChanged(id);
 
     // Draw frame
     const ImU32 frame_col = GetColorU32(g.ActiveId == id ? ImGuiCol_FrameBgActive : g.HoveredId == id ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg);
@@ -10005,7 +10030,10 @@ bool ImGui::Checkbox(const char* label, bool* v)
     bool hovered, held;
     bool pressed = ButtonBehavior(total_bb, id, &hovered, &held);
     if (pressed)
+    {
         *v = !(*v);
+        MarkItemValueChanged(id);
+    }
 
     RenderNavHighlight(total_bb, id);
     RenderFrame(check_bb.Min, check_bb.Max, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), true, style.FrameRounding);
@@ -10073,6 +10101,8 @@ bool ImGui::RadioButton(const char* label, bool active)
 
     bool hovered, held;
     bool pressed = ButtonBehavior(total_bb, id, &hovered, &held);
+    if (pressed)
+        MarkItemValueChanged(id);
 
     RenderNavHighlight(total_bb, id);
     window->DrawList->AddCircleFilled(center, radius, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), 16);
@@ -10969,6 +10999,9 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
     if (label_size.x > 0)
         RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);
 
+    if (value_changed)
+        MarkItemValueChanged(id);
+
     if ((flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0)
         return enter_pressed;
     else
@@ -11433,6 +11466,8 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
             g.NavDisableHighlight = true;
             SetNavID(id, window->DC.NavLayerCurrent);
         }
+    if (pressed)
+        MarkItemValueChanged(id);
 
     // Render
     if (hovered || selected)
@@ -12025,6 +12060,9 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
     if (!(flags & ImGuiColorEditFlags_NoTooltip) && hovered)
         ColorTooltip(desc_id, &col.x, flags & (ImGuiColorEditFlags_NoAlpha | ImGuiColorEditFlags_AlphaPreview | ImGuiColorEditFlags_AlphaPreviewHalf));
 
+    if (pressed)
+        MarkItemValueChanged(id);
+
     return pressed;
 }
 
@@ -12319,6 +12357,9 @@ bool ImGui::ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flag
     if (picker_active_window && g.ActiveId != 0 && g.ActiveIdWindow == picker_active_window)
         window->DC.LastItemId = g.ActiveId;
 
+    if (value_changed)
+        MarkItemValueChanged(window->DC.LastItemId);
+
     return value_changed;
 }
 
@@ -12642,9 +12683,15 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
     }
 
     EndGroup();
+
+    if (value_changed && memcmp(backup_initial_col, col, components * sizeof(float)) == 0)
+        value_changed = false;
+    if (value_changed)
+        MarkItemValueChanged(window->DC.LastItemId);
+
     PopID();
 
-    return value_changed && memcmp(backup_initial_col, col, components * sizeof(float));
+    return value_changed;
 }
 
 // Horizontal separating line.
@@ -12752,6 +12799,8 @@ bool ImGui::SplitterBehavior(ImGuiID id, const ImRect& bb, ImGuiAxis axis, float
         *size1 += mouse_delta;
         *size2 -= mouse_delta;
         bb_render.Translate((axis == ImGuiAxis_X) ? ImVec2(mouse_delta, 0.0f) : ImVec2(0.0f, mouse_delta));
+
+        MarkItemValueChanged(id);
     }
 
     // Render

imgui.h

@@ -506,7 +506,8 @@ namespace ImGui
     IMGUI_API bool          IsItemFocused();                                                    // is the last item focused for keyboard/gamepad navigation?
     IMGUI_API bool          IsItemClicked(int mouse_button = 0);                                // is the last item clicked? (e.g. button/node just clicked on) == IsMouseClicked(mouse_button) && IsItemHovered()
     IMGUI_API bool          IsItemVisible();                                                    // is the last item visible? (items may be out of sight because of clipping/scrolling)
-    IMGUI_API bool          IsItemDeactivated();                                                // was the last item just made inactive (item was previously active), useful for Undo/Redo patterns.
+    IMGUI_API bool          IsItemDeactivated();                                                // was the last item just made inactive (item was previously active). Useful for Undo/Redo patterns with widgets that requires continuous editing.
+    IMGUI_API bool          IsItemDeactivatedAfterChange();                                     // was the last item just made inactive and made a value change when it was active? (e.g. Slider/Drag moved). Useful for Undo/Redo patterns with widgets that requires continuous editing. Note that you may get false positives (some widgets such as Combo()/ListBox()/Selectable() will return true even when clicking an already selected item).
     IMGUI_API bool          IsAnyItemHovered();
     IMGUI_API bool          IsAnyItemActive();
     IMGUI_API bool          IsAnyItemFocused();

imgui_demo.cpp

@@ -1178,18 +1178,21 @@ void ImGui::ShowDemoWindow(bool* p_open)
             // Display the value of IsItemHovered() and other common item state functions. Note that the flags can be combined.
             // (because BulletText is an item itself and that would affect the output of IsItemHovered() we pass all state in a single call to simplify the code).
             static int item_type = 1;
+            static bool b = false;
             static float col4f[4] = { 1.0f, 0.5, 0.0f, 1.0f };
             ImGui::RadioButton("Text", &item_type, 0); ImGui::SameLine();
             ImGui::RadioButton("Button", &item_type, 1); ImGui::SameLine();
-            ImGui::RadioButton("SliderFloat", &item_type, 2); ImGui::SameLine();
-            ImGui::RadioButton("ColorEdit4", &item_type, 3); ImGui::SameLine();
-            ImGui::RadioButton("ListBox", &item_type, 4);
+            ImGui::RadioButton("CheckBox", &item_type, 2); ImGui::SameLine();
+            ImGui::RadioButton("SliderFloat", &item_type, 3); ImGui::SameLine();
+            ImGui::RadioButton("ColorEdit4", &item_type, 4); ImGui::SameLine();
+            ImGui::RadioButton("ListBox", &item_type, 5);
             bool ret = false;
             if (item_type == 0) { ImGui::Text("ITEM: Text"); }                                              // Testing text items with no identifier/interaction
             if (item_type == 1) { ret = ImGui::Button("ITEM: Button"); }                                    // Testing button
-            if (item_type == 2) { ret = ImGui::SliderFloat("ITEM: SliderFloat", &col4f[0], 0.0f, 1.0f); }   // Testing basic item
-            if (item_type == 3) { ret = ImGui::ColorEdit4("ITEM: ColorEdit4", col4f); }                     // Testing multi-component items (IsItemXXX flags are reported merged)
-            if (item_type == 4) { const char* items[] = { "Apple", "Banana", "Cherry" }; static int current = 1; ret = ImGui::ListBox("ITEM: ListBox", &current, items, IM_ARRAYSIZE(items), IM_ARRAYSIZE(items)); }
+            if (item_type == 2) { ret = ImGui::Checkbox("ITEM: CheckBox", &b); }                            // Testing checkbox
+            if (item_type == 3) { ret = ImGui::SliderFloat("ITEM: SliderFloat", &col4f[0], 0.0f, 1.0f); }   // Testing basic item
+            if (item_type == 4) { ret = ImGui::ColorEdit4("ITEM: ColorEdit4", col4f); }                     // Testing multi-component items (IsItemXXX flags are reported merged)
+            if (item_type == 5) { const char* items[] = { "Apple", "Banana", "Cherry", "Kiwi" }; static int current = 1; ret = ImGui::ListBox("ITEM: ListBox", &current, items, IM_ARRAYSIZE(items), IM_ARRAYSIZE(items)); }
             ImGui::BulletText(
                 "Return value = %d\n"
                 "IsItemFocused() = %d\n"
@@ -1200,6 +1203,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
                 "IsItemHovered(_RectOnly) = %d\n"
                 "IsItemActive() = %d\n"
                 "IsItemDeactivated() = %d\n"
+                "IsItemDeactivatedAfterChange() = %d\n"
                 "IsItemVisible() = %d\n",
                 ret,
                 ImGui::IsItemFocused(),
@@ -1210,6 +1214,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
                 ImGui::IsItemHovered(ImGuiHoveredFlags_RectOnly),
                 ImGui::IsItemActive(),
                 ImGui::IsItemDeactivated(),
+                ImGui::IsItemDeactivatedAfterChange(),
                 ImGui::IsItemVisible()
             );
 

imgui_internal.h

@@ -625,7 +625,9 @@ struct ImGuiContext
     bool                    ActiveIdIsAlive;                    // Active widget has been seen this frame
     bool                    ActiveIdIsJustActivated;            // Set at the time of activation for one frame
     bool                    ActiveIdAllowOverlap;               // Active widget allows another widget to steal active id (generally for overlapping widgets, but not always)
+    bool                    ActiveIdValueChanged;
     bool                    ActiveIdPreviousFrameIsAlive;
+    bool                    ActiveIdPreviousFrameValueChanged;
     int                     ActiveIdAllowNavDirFlags;           // Active widget allows using directional navigation (e.g. can activate a button and move away from it)
     ImVec2                  ActiveIdClickOffset;                // Clicked offset from upper-left corner, if applicable (currently only set by ButtonBehavior)
     ImGuiWindow*            ActiveIdWindow;
@@ -765,7 +767,9 @@ struct ImGuiContext
         ActiveIdIsAlive = false;
         ActiveIdIsJustActivated = false;
         ActiveIdAllowOverlap = false;
+        ActiveIdValueChanged = false;
         ActiveIdPreviousFrameIsAlive = false;
+        ActiveIdPreviousFrameValueChanged = false;
         ActiveIdAllowNavDirFlags = 0;
         ActiveIdClickOffset = ImVec2(-1,-1);
         ActiveIdWindow = ActiveIdPreviousFrameWindow = NULL;
@@ -1082,6 +1086,7 @@ namespace ImGui
     IMGUI_API ImGuiID       GetHoveredID();
     IMGUI_API void          SetHoveredID(ImGuiID id);
     IMGUI_API void          KeepAliveID(ImGuiID id);
+    IMGUI_API void          MarkItemValueChanged(ImGuiID id);
 
     IMGUI_API void          ItemSize(const ImVec2& size, float text_offset_y = 0.0f);
     IMGUI_API void          ItemSize(const ImRect& bb, float text_offset_y = 0.0f);