Internals: ItemAdd: set LastItemXXX fields before navigation calls + comments about io.IniFilename (#4294)

imgui.cpp

@@ -1070,7 +1070,7 @@ ImGuiIO::ImGuiIO()
     DisplaySize = ImVec2(-1.0f, -1.0f);
     DeltaTime = 1.0f / 60.0f;
     IniSavingRate = 5.0f;
-    IniFilename = "imgui.ini";
+    IniFilename = "imgui.ini"; // Important: "imgui.ini" is relative to current working dir, most apps will want to lock this to an absolute path (e.g. same path as executables).
     LogFilename = "imgui_log.txt";
     MouseDoubleClickTime = 0.30f;
     MouseDoubleClickMaxDist = 6.0f;
@@ -3278,6 +3278,7 @@ void ImGui::SetLastItemData(ImGuiWindow* window, ImGuiID item_id, ImGuiItemFlags
     window->DC.LastItemRect = item_rect;
 }
 
+// Called by ItemAdd()
 // Process TAB/Shift+TAB. Be mindful that this function may _clear_ the ActiveID when tabbing out.
 void ImGui::ItemFocusable(ImGuiWindow* window, ImGuiID id)
 {
@@ -7455,9 +7456,17 @@ bool ImGui::ItemAdd(const ImRect& bb, ImGuiID id, const ImRect* nav_bb_arg, ImGu
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
 
+    // Equivalent to calling SetLastItemData()
+    window->DC.LastItemId = id;
+    window->DC.LastItemRect = bb;
+    window->DC.LastItemInFlags = g.CurrentItemFlags;
+    window->DC.LastItemStatusFlags = ImGuiItemStatusFlags_None;
+    g.NextItemData.Flags = ImGuiNextItemDataFlags_None;
+
+    // Directional navigation processing
     if (id != 0)
     {
-        // Navigation processing runs prior to clipping early-out
+        // Runs prior to clipping early-out
         //  (a) So that NavInitRequest can be honored, for newly opened windows to select a default widget
         //  (b) So that we can scroll up/down past clipped items. This adds a small O(N) cost to regular navigation requests
         //      unfortunately, but it is still limited to one window. It may not scale very well for windows with ten of
@@ -7482,13 +7491,6 @@ bool ImGui::ItemAdd(const ImRect& bb, ImGuiID id, const ImRect* nav_bb_arg, ImGu
 #endif
     }
 
-    // Equivalent to calling SetLastItemData()
-    window->DC.LastItemId = id;
-    window->DC.LastItemRect = bb;
-    window->DC.LastItemInFlags = g.CurrentItemFlags;
-    window->DC.LastItemStatusFlags = ImGuiItemStatusFlags_None;
-    g.NextItemData.Flags = ImGuiNextItemDataFlags_None;
-
 #ifdef IMGUI_ENABLE_TEST_ENGINE
     if (id != 0)
         IMGUI_TEST_ENGINE_ITEM_ADD(nav_bb_arg ? *nav_bb_arg : bb, id);
@@ -8856,7 +8858,7 @@ static void ImGui::NavProcessItem(ImGuiWindow* window, const ImRect& nav_bb, con
     //if (!g.IO.NavActive)  // [2017/10/06] Removed this possibly redundant test but I am not sure of all the side-effects yet. Some of the feature here will need to work regardless of using a _NoNavInputs flag.
     //    return;
 
-    const ImGuiItemFlags item_flags = g.CurrentItemFlags;
+    const ImGuiItemFlags item_flags = window->DC.LastItemInFlags;
     const ImRect nav_bb_rel(nav_bb.Min - window->Pos, nav_bb.Max - window->Pos);
 
     // Process Init Request
@@ -9885,6 +9887,7 @@ bool ImGui::BeginDragDropSource(ImGuiDragDropFlags flags)
             // We build a throwaway ID based on current ID stack + relative AABB of items in window.
             // THE IDENTIFIER WON'T SURVIVE ANY REPOSITIONING OF THE WIDGET, so if your widget moves your dragging operation will be canceled.
             // We don't need to maintain/call ClearActiveID() as releasing the button will early out this function and trigger !ActiveIdIsAlive.
+            // Rely on keeping other window->LastItemXXX fields intact.
             source_id = window->DC.LastItemId = window->GetIDFromRectangle(window->DC.LastItemRect);
             bool is_hovered = ItemHoverable(window->DC.LastItemRect, source_id);
             if (is_hovered && g.IO.MouseClicked[mouse_button])

imgui.h

@@ -898,6 +898,7 @@ namespace ImGui
     // Settings/.Ini Utilities
     // - The disk functions are automatically called if io.IniFilename != NULL (default is "imgui.ini").
     // - Set io.IniFilename to NULL to load/save manually. Read io.WantSaveIniSettings description about handling .ini saving manually.
+    // - Important: default value "imgui.ini" is relative to current working dir! Most apps will want to lock this to an absolute path (e.g. same path as executables).
     IMGUI_API void          LoadIniSettingsFromDisk(const char* ini_filename);                  // call after CreateContext() and before the first call to NewFrame(). NewFrame() automatically calls LoadIniSettingsFromDisk(io.IniFilename).
     IMGUI_API void          LoadIniSettingsFromMemory(const char* ini_data, size_t ini_size=0); // call after CreateContext() and before the first call to NewFrame() to provide .ini data from your own data source.
     IMGUI_API void          SaveIniSettingsToDisk(const char* ini_filename);                    // this is automatically called (if io.IniFilename is not empty) a few seconds after any modification that should be reflected in the .ini file (and also by DestroyContext).
@@ -1800,7 +1801,7 @@ struct ImGuiIO
     ImVec2      DisplaySize;                    // <unset>          // Main display size, in pixels (generally == GetMainViewport()->Size)
     float       DeltaTime;                      // = 1.0f/60.0f     // Time elapsed since last frame, in seconds.
     float       IniSavingRate;                  // = 5.0f           // Minimum time between saving positions/sizes to .ini file, in seconds.
-    const char* IniFilename;                    // = "imgui.ini"    // Path to .ini file. Set NULL to disable automatic .ini loading/saving, if e.g. you want to manually load/save from memory.
+    const char* IniFilename;                    // = "imgui.ini"    // Path to .ini file (important: default "imgui.ini" is relative to current working dir!). Set NULL to disable automatic .ini loading/saving or if you want to manually call LoadIniSettingsXXX() / SaveIniSettingsXXX() functions.
     const char* LogFilename;                    // = "imgui_log.txt"// Path to .log file (default parameter to ImGui::LogToFile when no file is specified).
     float       MouseDoubleClickTime;           // = 0.30f          // Time for a double-click, in seconds.
     float       MouseDoubleClickMaxDist;        // = 6.0f           // Distance threshold to stay in to validate a double-click, in pixels.

imgui_widgets.cpp

@@ -682,6 +682,7 @@ bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags
 
     if (g.CurrentItemFlags & ImGuiItemFlags_ButtonRepeat)
         flags |= ImGuiButtonFlags_Repeat;
+
     bool hovered, held;
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);