IsItemHovered: Added ImGuiHoveredFlags_DelayNormal, ImGuiHoveredFlags_DelayShort, ImGuiHoveredFlags_NoSharedDelay. (#1485)

IsItemHovered() can't have a non-zero default, but higher-level tooltip helpers may enable a different default later.

docs/CHANGELOG.txt

@@ -67,6 +67,11 @@ Other Changes:
   Enter keep the input active and select all text.
 - InputText: numerical fields automatically accept full-width characters (U+FF01..U+FF5E)
   by converting them to half-width (U+0021..U+007E).
+- IsItemHovered: Added ImGuiHoveredFlags_DelayNormal and ImGuiHoveredFlags_DelayShort flags,
+  allowing to introduce a shared delay for tooltip idioms. The delays are respectively
+  io.HoverDelayNormal (default to 0.30f) and io.HoverDelayFast (default to 0.10f). (#1485)
+- IsItemHovered: Added ImGuiHoveredFlags_NoSharedDelay to disable sharing delays between itemm,
+  so moving from one item to a nearby one will requires delay to elapse again. (#1485)
 - Tables,Columns: fixed a layout issue where SameLine() prior to a row change would set the
   next row in such state where subsequent SameLine() would move back to previous row.
 - Tabs: Fixed a crash when closing multiple windows (possible with docking only) with an

imgui.cpp

@@ -1147,6 +1147,8 @@ ImGuiIO::ImGuiIO()
 #endif
     KeyRepeatDelay = 0.275f;
     KeyRepeatRate = 0.050f;
+    HoverDelayNormal = 0.30f;
+    HoverDelayShort = 0.10f;
     UserData = NULL;
 
     Fonts = NULL;
@@ -3571,6 +3573,24 @@ bool ImGui::IsItemHovered(ImGuiHoveredFlags flags)
             return false;
     }
 
+    // Handle hover delay
+    // (some ideas: https://www.nngroup.com/articles/timing-exposing-content)
+    float delay;
+    if (flags & ImGuiHoveredFlags_DelayNormal)
+        delay = g.IO.HoverDelayNormal;
+    else if (flags & ImGuiHoveredFlags_DelayShort)
+        delay = g.IO.HoverDelayShort;
+    else
+        delay = 0.0f;
+    if (delay > 0.0f)
+    {
+        ImGuiID hover_delay_id = (g.LastItemData.ID != 0) ? g.LastItemData.ID : window->GetIDFromRectangle(g.LastItemData.Rect);
+        if ((flags & ImGuiHoveredFlags_NoSharedDelay) && (g.HoverDelayIdPreviousFrame != hover_delay_id))
+            g.HoverDelayTimer = 0.0f;
+        g.HoverDelayId = hover_delay_id;
+        return g.HoverDelayTimer >= delay;
+    }
+
     return true;
 }
 
@@ -4466,6 +4486,23 @@ void ImGui::NewFrame()
     }
 #endif
 
+    // Update hover delay for IsItemHovered() with delays and tooltips
+    g.HoverDelayIdPreviousFrame = g.HoverDelayId;
+    if (g.HoverDelayId != 0)
+    {
+        //if (g.IO.MouseDelta.x == 0.0f && g.IO.MouseDelta.y == 0.0f) // Need design/flags
+        g.HoverDelayTimer += g.IO.DeltaTime;
+        g.HoverDelayClearTimer = 0.0f;
+        g.HoverDelayId = 0;
+    }
+    else if (g.HoverDelayTimer > 0.0f)
+    {
+        // This gives a little bit of leeway before clearing the hover timer, allowing mouse to cross gaps
+        g.HoverDelayClearTimer += g.IO.DeltaTime;
+        if (g.HoverDelayClearTimer >= ImMax(0.20f, g.IO.DeltaTime * 2.0f)) // ~6 frames at 30 Hz + allow for low framerate
+            g.HoverDelayTimer = g.HoverDelayClearTimer = 0.0f; // May want a decaying timer, in which case need to clamp at max first, based on max of caller last requested timer.
+    }
+
     // Drag and drop
     g.DragDropAcceptIdPrev = g.DragDropAcceptIdCurr;
     g.DragDropAcceptIdCurr = 0;
@@ -12381,7 +12418,7 @@ void ImGui::DebugTextEncoding(const char* str)
 static void MetricsHelpMarker(const char* desc)
 {
     ImGui::TextDisabled("(?)");
-    if (ImGui::IsItemHovered())
+    if (ImGui::IsItemHovered(ImGuiHoveredFlags_DelayShort))
     {
         ImGui::BeginTooltip();
         ImGui::PushTextWrapPos(ImGui::GetFontSize() * 35.0f);
@@ -12756,6 +12793,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             active_id_using_key_input_count += g.ActiveIdUsingKeyInputMask[n] ? 1 : 0;
         Text("ActiveIdUsing: NavDirMask: %X, KeyInputMask: %d key(s)", g.ActiveIdUsingNavDirMask, active_id_using_key_input_count);
         Text("HoveredId: 0x%08X (%.2f sec), AllowOverlap: %d", g.HoveredIdPreviousFrame, g.HoveredIdTimer, g.HoveredIdAllowOverlap); // Not displaying g.HoveredId as it is update mid-frame
+        Text("HoverDelayId: 0x%08X, Timer: %.2f, ClearTimer: %.2f", g.HoverDelayId, g.HoverDelayTimer, g.HoverDelayClearTimer);
         Text("DragDrop: %d, SourceId = 0x%08X, Payload \"%s\" (%d bytes)", g.DragDropActive, g.DragDropPayload.SourceId, g.DragDropPayload.DataType, g.DragDropPayload.DataSize);
         Unindent();
 

imgui.h

@@ -65,7 +65,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.89 WIP"
-#define IMGUI_VERSION_NUM           18810
+#define IMGUI_VERSION_NUM           18811
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 
@@ -1283,6 +1283,11 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_NoNavOverride                 = 1 << 10,  // Disable using gamepad/keyboard navigation state when active, always query mouse.
     ImGuiHoveredFlags_RectOnly                      = ImGuiHoveredFlags_AllowWhenBlockedByPopup | ImGuiHoveredFlags_AllowWhenBlockedByActiveItem | ImGuiHoveredFlags_AllowWhenOverlapped,
     ImGuiHoveredFlags_RootAndChildWindows           = ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_ChildWindows,
+
+    // Hovering delays (for tooltips)
+    ImGuiHoveredFlags_DelayNormal                   = 1 << 11,  // Return true after io.HoverDelayNormal elapsed (~0.30 sec)
+    ImGuiHoveredFlags_DelayShort                    = 1 << 12,  // Return true after io.HoverDelayShort elapsed (~0.10 sec)
+    ImGuiHoveredFlags_NoSharedDelay                 = 1 << 13,  // Disable shared delay system where moving from one item to the next keeps the previous timer for a short time (standard for tooltips with long delays)
 };
 
 // Flags for ImGui::BeginDragDropSource(), ImGui::AcceptDragDropPayload()
@@ -1905,6 +1910,8 @@ struct ImGuiIO
     float       MouseDragThreshold;             // = 6.0f           // Distance threshold before considering we are dragging.
     float       KeyRepeatDelay;                 // = 0.275f         // When holding a key/button, time before it starts repeating, in seconds (for buttons in Repeat mode, etc.).
     float       KeyRepeatRate;                  // = 0.050f         // When holding a key/button, rate at which it repeats, in seconds.
+    float       HoverDelayNormal;               // = 0.30 sec       // Delay on hovering before IsItemHovered(ImGuiHoveredFlags_DelayNormal) returns true.
+    float       HoverDelayShort;                // = 0.10 sec       // Delay on hovering before IsItemHovered(ImGuiHoveredFlags_DelayShort) returns true.
     void*       UserData;                       // = NULL           // Store your own data for retrieval by callbacks.
 
     ImFontAtlas*Fonts;                          // <auto>           // Font atlas: load, rasterize and pack one or more fonts into a single texture.

imgui_demo.cpp

@@ -191,7 +191,7 @@ static void ShowExampleMenuFile();
 static void HelpMarker(const char* desc)
 {
     ImGui::TextDisabled("(?)");
-    if (ImGui::IsItemHovered())
+    if (ImGui::IsItemHovered(ImGuiHoveredFlags_DelayShort))
     {
         ImGui::BeginTooltip();
         ImGui::PushTextWrapPos(ImGui::GetFontSize() * 35.0f);
@@ -633,22 +633,6 @@ static void ShowDemoWindowWidgets()
         ImGui::SameLine();
         ImGui::Text("%d", counter);
 
-        IMGUI_DEMO_MARKER("Widgets/Basic/Tooltips");
-        ImGui::Text("Hover over me");
-        if (ImGui::IsItemHovered())
-            ImGui::SetTooltip("I am a tooltip");
-
-        ImGui::SameLine();
-        ImGui::Text("- or me");
-        if (ImGui::IsItemHovered())
-        {
-            ImGui::BeginTooltip();
-            ImGui::Text("I am a fancy tooltip");
-            static float arr[] = { 0.6f, 0.1f, 1.0f, 0.5f, 0.92f, 0.1f, 0.2f };
-            ImGui::PlotLines("Curve", arr, IM_ARRAYSIZE(arr));
-            ImGui::EndTooltip();
-        }
-
         ImGui::Separator();
         ImGui::LabelText("label", "Value");
 
@@ -772,6 +756,40 @@ static void ShowDemoWindowWidgets()
                 "Using the simplified one-liner ListBox API here.\nRefer to the \"List boxes\" section below for an explanation of how to use the more flexible and general BeginListBox/EndListBox API.");
         }
 
+        {
+            // Tooltips
+            IMGUI_DEMO_MARKER("Widgets/Basic/Tooltips");
+            ImGui::AlignTextToFramePadding();
+            ImGui::Text("Tooltips:");
+
+            ImGui::SameLine();
+            ImGui::Button("Button");
+            if (ImGui::IsItemHovered())
+                ImGui::SetTooltip("I am a tooltip");
+
+            ImGui::SameLine();
+            ImGui::Button("Fancy");
+            if (ImGui::IsItemHovered())
+            {
+                ImGui::BeginTooltip();
+                ImGui::Text("I am a fancy tooltip");
+                static float arr[] = { 0.6f, 0.1f, 1.0f, 0.5f, 0.92f, 0.1f, 0.2f };
+                ImGui::PlotLines("Curve", arr, IM_ARRAYSIZE(arr));
+                ImGui::Text("Sin(time) = %f", sinf((float)ImGui::GetTime()));
+                ImGui::EndTooltip();
+            }
+
+            ImGui::SameLine();
+            ImGui::Button("Delayed");
+            if (ImGui::IsItemHovered(ImGuiHoveredFlags_DelayNormal)) // Delay best used on items that highlight on hover, so this not a great example!
+                ImGui::SetTooltip("I am a tooltip with a delay.");
+
+            ImGui::SameLine();
+            HelpMarker(
+                "Tooltip are created by using the IsItemHovered() function over any kind of item.");
+
+        }
+
         ImGui::TreePop();
     }
 
@@ -2346,6 +2364,10 @@ static void ShowDemoWindowWidgets()
         if (item_type == 14){ const char* items[] = { "Apple", "Banana", "Cherry", "Kiwi" }; static int current = 1; ret = ImGui::Combo("ITEM: Combo", &current, items, IM_ARRAYSIZE(items)); }
         if (item_type == 15){ const char* items[] = { "Apple", "Banana", "Cherry", "Kiwi" }; static int current = 1; ret = ImGui::ListBox("ITEM: ListBox", &current, items, IM_ARRAYSIZE(items), IM_ARRAYSIZE(items)); }
 
+        bool hovered_delay_none = ImGui::IsItemHovered();
+        bool hovered_delay_short = ImGui::IsItemHovered(ImGuiHoveredFlags_DelayShort);
+        bool hovered_delay_normal = ImGui::IsItemHovered(ImGuiHoveredFlags_DelayNormal);
+
         // Display the values of IsItemHovered() and other common item state functions.
         // Note that the ImGuiHoveredFlags_XXX flags can be combined.
         // Because BulletText is an item itself and that would affect the output of IsItemXXX functions,
@@ -2390,6 +2412,8 @@ static void ShowDemoWindowWidgets()
             ImGui::GetItemRectMax().x, ImGui::GetItemRectMax().y,
             ImGui::GetItemRectSize().x, ImGui::GetItemRectSize().y
         );
+        ImGui::BulletText(
+            "w/ Hovering Delay: None = %d, Fast %d, Normal = %d", hovered_delay_none, hovered_delay_short, hovered_delay_normal);
 
         if (item_disabled)
             ImGui::EndDisabled();

imgui_internal.h

@@ -1781,6 +1781,12 @@ struct ImGuiContext
     ImVector<ImGuiPtrOrIndex>       CurrentTabBarStack;
     ImVector<ImGuiShrinkWidthItem>  ShrinkWidthBuffer;
 
+    // Hover Delay system
+    ImGuiID                 HoverDelayId;
+    ImGuiID                 HoverDelayIdPreviousFrame;
+    float                   HoverDelayTimer;                    // Currently used IsItemHovered(), generally inferred from g.HoveredIdTimer but kept uncleared until clear timer elapse.
+    float                   HoverDelayClearTimer;               // Currently used IsItemHovered(): grace time before g.TooltipHoverTimer gets cleared.
+
     // Widget state
     ImVec2                  MouseLastValidPos;
     ImGuiInputTextState     InputTextState;
@@ -1802,7 +1808,6 @@ struct ImGuiContext
     float                   DisabledAlphaBackup;                // Backup for style.Alpha for BeginDisabled()
     short                   DisabledStackSize;
     short                   TooltipOverrideCount;
-    float                   TooltipSlowDelay;                   // Time before slow tooltips appears (FIXME: This is temporary until we merge in tooltip timer+priority work)
     ImVector<char>          ClipboardHandlerData;               // If no custom clipboard handler is defined
     ImVector<ImGuiID>       MenusIdSubmittedThisFrame;          // A list of menu IDs that were rendered at least once
 
@@ -1962,6 +1967,9 @@ struct ImGuiContext
         TablesTempDataStacked = 0;
         CurrentTabBar = NULL;
 
+        HoverDelayId = HoverDelayIdPreviousFrame = 0;
+        HoverDelayTimer = HoverDelayClearTimer = 0.0f;
+
         TempInputId = 0;
         ColorEditOptions = ImGuiColorEditFlags_DefaultOptions_;
         ColorEditLastHue = ColorEditLastSat = 0.0f;
@@ -1972,11 +1980,10 @@ struct ImGuiContext
         DragCurrentAccumDirty = false;
         DragCurrentAccum = 0.0f;
         DragSpeedDefaultRatio = 1.0f / 100.0f;
+        ScrollbarClickDeltaToGrabCenter = 0.0f;
         DisabledAlphaBackup = 0.0f;
         DisabledStackSize = 0;
-        ScrollbarClickDeltaToGrabCenter = 0.0f;
         TooltipOverrideCount = 0;
-        TooltipSlowDelay = 0.50f;
 
         PlatformImeData.InputPos = ImVec2(0.0f, 0.0f);
         PlatformImeDataPrev.InputPos = ImVec2(-1.0f, -1.0f); // Different to ensure initial submission

imgui_tables.cpp

@@ -2994,7 +2994,7 @@ void ImGui::TableHeader(const char* label)
     RenderTextEllipsis(window->DrawList, label_pos, ImVec2(ellipsis_max, label_pos.y + label_height + g.Style.FramePadding.y), ellipsis_max, ellipsis_max, label, label_end, &label_size);
 
     const bool text_clipped = label_size.x > (ellipsis_max - label_pos.x);
-    if (text_clipped && hovered && g.HoveredIdNotActiveTimer > g.TooltipSlowDelay)
+    if (text_clipped && hovered && g.ActiveId == 0 && IsItemHovered(ImGuiHoveredFlags_DelayNormal))
         SetTooltip("%.*s", (int)(label_end - label), label);
 
     // We don't use BeginPopupContextItem() because we want the popup to stay up even after the column is hidden

imgui_widgets.cpp

@@ -8288,8 +8288,9 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
     // (We test IsItemHovered() to discard e.g. when another item is active or drag and drop over the tab bar, which g.HoveredId ignores)
     // FIXME: This is a mess.
     // FIXME: We may want disabled tab to still display the tooltip?
-    if (text_clipped && g.HoveredId == id && !held && g.HoveredIdNotActiveTimer > g.TooltipSlowDelay && IsItemHovered())
+    if (text_clipped && g.HoveredId == id && !held)
         if (!(tab_bar->Flags & ImGuiTabBarFlags_NoTooltip) && !(tab->Flags & ImGuiTabItemFlags_NoTooltip))
+            if (IsItemHovered(ImGuiHoveredFlags_DelayNormal))
                 SetTooltip("%.*s", (int)(FindRenderedTextEnd(label) - label), label);
 
     IM_ASSERT(!is_tab_button || !(tab_bar->SelectedTabId == tab->ID && is_tab_button)); // TabItemButton should not be selected