TreeNode, Tables: fixed ImGuiTreeNodeFlags_DrawLinesXXX feature when TreePop() is called from a different column. (#2920)

Author: ocornut

imgui_internal.h

@@ -212,6 +212,10 @@ typedef int ImGuiTooltipFlags;          // -> enum ImGuiTooltipFlags_       // F
 typedef int ImGuiTypingSelectFlags;     // -> enum ImGuiTypingSelectFlags_  // Flags: for GetTypingSelectRequest()
 typedef int ImGuiWindowRefreshFlags;    // -> enum ImGuiWindowRefreshFlags_ // Flags: for SetNextWindowRefreshPolicy()
 
+// Table column indexing
+typedef ImS16 ImGuiTableColumnIdx;
+typedef ImU16 ImGuiTableDrawChannelIdx;
+
 //-----------------------------------------------------------------------------
 // [SECTION] Context pointer
 // See implementation of this variable in imgui.cpp for comments and details.
@@ -1315,6 +1319,7 @@ struct ImGuiTreeNodeStackData
     ImRect                  NavRect;        // Used for nav landing
     float                   DrawLinesX1;
     float                   DrawLinesY2;
+    ImGuiTableColumnIdx     DrawLinesTableColumn;
 };
 
 // sizeof() = 20
@@ -2942,11 +2947,7 @@ struct IMGUI_API ImGuiTabBar
 //-----------------------------------------------------------------------------
 
 #define IM_COL32_DISABLE                IM_COL32(0,0,0,1)   // Special sentinel code which cannot be used as a regular color.
-#define IMGUI_TABLE_MAX_COLUMNS         512                 // May be further lifted
-
-// Our current column maximum is 64 but we may raise that in the future.
-typedef ImS16 ImGuiTableColumnIdx;
-typedef ImU16 ImGuiTableDrawChannelIdx;
+#define IMGUI_TABLE_MAX_COLUMNS         512                 // Arbitrary "safety" maximum, may be lifted in the future if needed. Must fit in ImGuiTableColumnIdx/ImGuiTableDrawChannelIdx.
 
 // [Internal] sizeof() ~ 112
 // We use the terminology "Enabled" to refer to a column that is not Hidden by user/api.
@@ -3641,6 +3642,8 @@ namespace ImGui
     IMGUI_API float         TableGetHeaderAngledMaxLabelWidth();
     IMGUI_API void          TablePushBackgroundChannel();
     IMGUI_API void          TablePopBackgroundChannel();
+    IMGUI_API void          TablePushColumnChannel(int column_n);
+    IMGUI_API void          TablePopColumnChannel();
     IMGUI_API void          TableAngledHeadersRowEx(ImGuiID row_id, float angle, float max_label_width, const ImGuiTableHeaderData* data, int data_count);
 
     // Tables: Internals

imgui_tables.cpp

@@ -2193,6 +2193,7 @@ void ImGui::TableBeginCell(ImGuiTable* table, int column_n)
         g.LastItemData.StatusFlags = 0;
     }
 
+    // Also see TablePushColumnChannel()
     if (table->Flags & ImGuiTableFlags_NoClip)
     {
         // FIXME: if we end up drawing all borders/bg in EndTable, could remove this and just assert that channel hasn't changed.
@@ -2466,10 +2467,38 @@ void ImGui::TablePopBackgroundChannel()
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     ImGuiTable* table = g.CurrentTable;
-    ImGuiTableColumn* column = &table->Columns[table->CurrentColumn];
 
     // Optimization: avoid PopClipRect() + SetCurrentChannel()
     SetWindowClipRectBeforeSetChannel(window, table->HostBackupInnerClipRect);
+    table->DrawSplitter->SetCurrentChannel(window->DrawList, table->Columns[table->CurrentColumn].DrawChannelCurrent);
+}
+
+// Also see TableBeginCell()
+void ImGui::TablePushColumnChannel(int column_n)
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiTable* table = g.CurrentTable;
+
+    // Optimization: avoid SetCurrentChannel() + PushClipRect()
+    if (table->Flags & ImGuiTableFlags_NoClip)
+        return;
+    ImGuiWindow* window = g.CurrentWindow;
+    const ImGuiTableColumn* column = &table->Columns[column_n];
+    SetWindowClipRectBeforeSetChannel(window, column->ClipRect);
+    table->DrawSplitter->SetCurrentChannel(window->DrawList, column->DrawChannelCurrent);
+}
+
+void ImGui::TablePopColumnChannel()
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiTable* table = g.CurrentTable;
+
+    // Optimization: avoid PopClipRect() + SetCurrentChannel()
+    if (table->Flags & ImGuiTableFlags_NoClip)
+        return;
+    ImGuiWindow* window = g.CurrentWindow;
+    const ImGuiTableColumn* column = &table->Columns[table->CurrentColumn];
+    SetWindowClipRectBeforeSetChannel(window, column->ClipRect);
     table->DrawSplitter->SetCurrentChannel(window->DrawList, column->DrawChannelCurrent);
 }
 

imgui_widgets.cpp

@@ -6569,7 +6569,9 @@ static void TreeNodeStoreStackData(ImGuiTreeNodeFlags flags, float x1)
     tree_node_data->NavRect = g.LastItemData.NavRect;
 
     // Initially I tried to latch value for GetColorU32(ImGuiCol_TreeLines) but it's not a good trade-off for very large trees.
-    tree_node_data->DrawLinesX1 = (flags & (ImGuiTreeNodeFlags_DrawLinesFull | ImGuiTreeNodeFlags_DrawLinesToNodes)) ? (x1 + g.FontSize * 0.5f + g.Style.FramePadding.x) : +FLT_MAX;
+    const bool draw_lines = (flags & (ImGuiTreeNodeFlags_DrawLinesFull | ImGuiTreeNodeFlags_DrawLinesToNodes)) != 0;
+    tree_node_data->DrawLinesX1 = draw_lines ? (x1 + g.FontSize * 0.5f + g.Style.FramePadding.x) : +FLT_MAX;
+    tree_node_data->DrawLinesTableColumn = draw_lines && g.CurrentTable ? (ImGuiTableColumnIdx)g.CurrentTable->CurrentColumn : -1;
     tree_node_data->DrawLinesY2 = -FLT_MAX;
     window->DC.TreeHasStackDataDepthMask |= (1 << window->DC.TreeDepth);
 }
@@ -6926,7 +6928,11 @@ void ImGui::TreePop()
             if (y1 < y2)
             {
                 float x = ImTrunc(data->DrawLinesX1);
+                if (data->DrawLinesTableColumn != -1)
+                    TablePushColumnChannel(data->DrawLinesTableColumn);
                 window->DrawList->AddLine(ImVec2(x, y1), ImVec2(x, y2), GetColorU32(ImGuiCol_TreeLines), g.Style.TreeLinesSize);
+                if (data->DrawLinesTableColumn != -1)
+                    TablePopColumnChannel();
             }
         }
         g.TreeNodeStack.pop_back();