Added IsItemActivated() as an extension to the IsItemDeactivated/IsItemDeactivatedAfterEdit functions which are useful to implement variety of undo patterns. (#820, #956, #1875)

docs/CHANGELOG.txt

@@ -43,10 +43,13 @@ Other Changes:
 - InputText: Fixed a bug where ESCAPE would be first captured by the Keyboard Navigation code. (#2321, #787)
 - InputText: Fixed redo buffer exhaustion handling (rare) which could corrupt the undo character buffer. (#2333)
   The way the redo/undo buffers work would have made it generally unnoticeable to the user.
+- Added IsItemActivated() as an extension to the IsItemDeactivated/IsItemDeactivatedAfterEdit functions
+  which are useful to implement variety of undo patterns. (#820, #956, #1875)
 - Fixed range-version of PushID() and GetID() not honoring the ### operator to restart from the seed value.
 - Fixed CloseCurrentPopup() on a child-menu of a modal incorrectly closing the modal. (#2308)
 - Tabs: Added ImGuiTabBarFlags_TabListPopupButton flag to show a popup button on manual tab bars. (#261, #351)
 - Tabs: Removed ImGuiTabBarFlags_NoTabListPopupButton which was available in 1.67 but actually had zero use.
+- Tabs: Fixed a minor clipping glitch when changing style's FramePadding from frame to frame.
 - RadioButton: Fixed label horizontal alignment to precisely match Checkbox().
 - Window: When resizing from an edge, the border is more visible and better follow the rounded corners.
 - ImDrawList: Fixed AddCircle(), AddCircleFilled() angle step being off, which was visible when drawing a "circle"

imgui.cpp

@@ -4215,6 +4215,18 @@ bool ImGui::IsItemActive()
     return false;
 }
 
+bool ImGui::IsItemActivated()
+{
+    ImGuiContext& g = *GImGui;
+    if (g.ActiveId)
+    {
+        ImGuiWindow* window = g.CurrentWindow;
+        if (g.ActiveId == window->DC.LastItemId && g.ActiveIdPreviousFrame != window->DC.LastItemId)
+            return true;
+    }
+    return false;
+}
+
 bool ImGui::IsItemDeactivated()
 {
     ImGuiContext& g = *GImGui;

imgui.h

@@ -607,6 +607,7 @@ namespace ImGui
     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          IsItemEdited();                                                     // did the last item modify its underlying value this frame? or was pressed? This is generally the same as the "bool" return value of many widgets.
+    IMGUI_API bool          IsItemActivated();                                                  // was the last item just made active (item was previously inactive).
     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          IsItemDeactivatedAfterEdit();                                       // 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_demo.cpp

@@ -1420,7 +1420,7 @@ static void ShowDemoWindowWidgets()
         static float col4f[4] = { 1.0f, 0.5, 0.0f, 1.0f };
         ImGui::RadioButton("Text", &item_type, 0);
         ImGui::RadioButton("Button", &item_type, 1);
-        ImGui::RadioButton("CheckBox", &item_type, 2);
+        ImGui::RadioButton("Checkbox", &item_type, 2);
         ImGui::RadioButton("SliderFloat", &item_type, 3);
         ImGui::RadioButton("ColorEdit4", &item_type, 4);
         ImGui::RadioButton("ListBox", &item_type, 5);
@@ -1428,7 +1428,7 @@ static void ShowDemoWindowWidgets()
         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::Checkbox("ITEM: CheckBox", &b); }                            // Testing checkbox
+        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)); }
@@ -1442,6 +1442,7 @@ static void ShowDemoWindowWidgets()
             "IsItemHovered(_RectOnly) = %d\n"
             "IsItemActive() = %d\n"
             "IsItemEdited() = %d\n"
+            "IsItemActivated() = %d\n"
             "IsItemDeactivated() = %d\n"
             "IsItemDeactivatedEdit() = %d\n"
             "IsItemVisible() = %d\n"
@@ -1457,6 +1458,7 @@ static void ShowDemoWindowWidgets()
             ImGui::IsItemHovered(ImGuiHoveredFlags_RectOnly),
             ImGui::IsItemActive(),
             ImGui::IsItemEdited(),
+            ImGui::IsItemActivated(),
             ImGui::IsItemDeactivated(),
             ImGui::IsItemDeactivatedAfterEdit(),
             ImGui::IsItemVisible(),