Tables: added Angled headers support. Added ImGuiTableColumnFlags_Ang…

…ledHeader, ImGui::TableHeadersAngledRow(), style.TableAngledHeadersAngle. (#2957)

docs/CHANGELOG.txt

@@ -94,17 +94,20 @@ Other changes:
 - Drag and Drop: Fixed submitting a tooltip from drop target location when using AcceptDragDropPayload()
   with ImGuiDragDropFlags_AcceptNoPreviewTooltip and submitting a tooltip manually.
 - TreeNode: Added ImGuiTreeNodeFlags_SpanAllColumns for use in tables. (#3151, #3565, #2451, #2438)
-- Tables: Added ImGuiTableFlags_HighlightHoveredColumn flag, currently highlighting column header.
-- Tables: Fixed an edge-case when no columns are visible + table scrollbar is visible + user
-  code is always testing return value of TableSetColumnIndex() to coarse clip. With an active
-  clipper it would have asserted. Without a clipper, the scrollbar range would be wrong.
-- Tables: Request user to submit contents when outer host-window is requesting auto-resize,
-  so a scrolling table can contribute to initial window size. (#6510)
-- Tables: Fixed subtle drawing overlap between borders in some situations.
-- Tables: Fixed bottom-most and right-most outer border offset by one. (#6765, #3752) [@v-ein]
-- Tables: Fixed top-most outer border being drawn with both TableBorderLight and TableBorderStrong
-  in some situations, causing the earlier to be visible underneath when alpha is not 1.0f.
-- Tables: fixed right-clicking right-most section (past right-most column) from highlighting a column.
+- Tables:
+  - Added angled headers support. You need to set ImGuiTableColumnFlags_AngledHeader on selected
+    columns and call TableAngledHeadersRow(). Added style.TableAngledHeadersAngle style option.
+  - Added ImGuiTableFlags_HighlightHoveredColumn flag, currently highlighting column header.
+  - Fixed an edge-case when no columns are visible + table scrollbar is visible + user
+    code is always testing return value of TableSetColumnIndex() to coarse clip. With an active
+    clipper it would have asserted. Without a clipper, the scrollbar range would be wrong.
+  - Request user to submit contents when outer host-window is requesting auto-resize,
+    so a scrolling table can contribute to initial window size. (#6510)
+  - Fixed subtle drawing overlap between borders in some situations.
+  - Fixed bottom-most and right-most outer border offset by one. (#6765, #3752) [@v-ein]
+  - Fixed top-most outer border being drawn with both TableBorderLight and TableBorderStrong
+    in some situations, causing the earlier to be visible underneath when alpha is not 1.0f.
+  - fixed right-clicking right-most section (past right-most column) from highlighting a column.
 - TabBar: Fixed position of unsaved document marker (ImGuiTabItemFlags_UnsavedDocument) which was
   accidentally offset in 1.89.9. (#6862) [@alektron]
 - Fonts: 'float size_pixels' passed to AddFontXXX() functions is now rounded to lowest integer.

imgui.cpp

@@ -1188,6 +1188,7 @@ ImGuiStyle::ImGuiStyle()
     TabBorderSize           = 0.0f;             // Thickness of border around tabs.
     TabMinWidthForCloseButton = 0.0f;           // Minimum width for close button to appear on an unselected tab when hovered. Set to 0.0f to always show when hovering, set to FLT_MAX to never show close button unless selected.
     TabBarBorderSize        = 1.0f;             // Thickness of tab-bar separator, which takes on the tab active color to denote focus.
+    TableAngledHeadersAngle = 35.0f * (IM_PI / 180.0f); // Angle of angled headers (supported values range from -50 degrees to +50 degrees).
     ColorButtonPosition     = ImGuiDir_Right;   // Side of the color button in the ColorEdit4 widget (left/right). Defaults to ImGuiDir_Right.
     ButtonTextAlign         = ImVec2(0.5f,0.5f);// Alignment of button text when button is larger than text.
     SelectableTextAlign     = ImVec2(0.0f,0.0f);// Alignment of selectable text. Defaults to (0.0f, 0.0f) (top-left aligned). It's generally important to keep this left-aligned if you want to lay multiple items on a same line.

imgui.h

@@ -771,8 +771,9 @@ namespace ImGui
     // - Use TableSetupScrollFreeze() to lock columns/rows so they stay visible when scrolled.
     IMGUI_API void          TableSetupColumn(const char* label, ImGuiTableColumnFlags flags = 0, float init_width_or_weight = 0.0f, ImGuiID user_id = 0);
     IMGUI_API void          TableSetupScrollFreeze(int cols, int rows);         // lock columns/rows so they stay visible when scrolled.
-    IMGUI_API void          TableHeadersRow();                                  // submit all headers cells based on data provided to TableSetupColumn() + submit context menu
     IMGUI_API void          TableHeader(const char* label);                     // submit one header cell manually (rarely used)
+    IMGUI_API void          TableHeadersRow();                                  // submit a row with headers cells based on data provided to TableSetupColumn() + submit context menu
+    IMGUI_API void          TableAngledHeadersRow();                            // submit a row with angled headers for every column with the ImGuiTableColumnFlags_AngledHeader flag. MUST BE FIRST ROW.
 
     // Tables: Sorting & Miscellaneous functions
     // - Sorting: call TableGetSortSpecs() to retrieve latest sort specs for the table. NULL when not sorting.
@@ -1240,12 +1241,13 @@ enum ImGuiTableColumnFlags_
     ImGuiTableColumnFlags_NoSort                = 1 << 9,   // Disable ability to sort on this field (even if ImGuiTableFlags_Sortable is set on the table).
     ImGuiTableColumnFlags_NoSortAscending       = 1 << 10,  // Disable ability to sort in the ascending direction.
     ImGuiTableColumnFlags_NoSortDescending      = 1 << 11,  // Disable ability to sort in the descending direction.
-    ImGuiTableColumnFlags_NoHeaderLabel         = 1 << 12,  // TableHeadersRow() will not submit label for this column. Convenient for some small columns. Name will still appear in context menu.
+    ImGuiTableColumnFlags_NoHeaderLabel         = 1 << 12,  // TableHeadersRow() will not submit horizontal label for this column. Convenient for some small columns. Name will still appear in context menu or in angled headers.
     ImGuiTableColumnFlags_NoHeaderWidth         = 1 << 13,  // Disable header text width contribution to automatic column width.
     ImGuiTableColumnFlags_PreferSortAscending   = 1 << 14,  // Make the initial sort direction Ascending when first sorting on this column (default).
     ImGuiTableColumnFlags_PreferSortDescending  = 1 << 15,  // Make the initial sort direction Descending when first sorting on this column.
     ImGuiTableColumnFlags_IndentEnable          = 1 << 16,  // Use current Indent value when entering cell (default for column 0).
     ImGuiTableColumnFlags_IndentDisable         = 1 << 17,  // Ignore current Indent value when entering cell (default for columns > 0). Indentation changes _within_ the cell will still be honored.
+    ImGuiTableColumnFlags_AngledHeader          = 1 << 18,  // TableHeadersRow() will submit an angled header row for this column. Note this will add an extra row.
 
     // Output status flags, read-only via TableGetColumnFlags()
     ImGuiTableColumnFlags_IsEnabled             = 1 << 24,  // Status: is enabled == not hidden by user/api (referred to as "Hide" in _DefaultHide and _NoHide) flags.
@@ -1926,6 +1928,7 @@ struct ImGuiStyle
     float       TabBorderSize;              // Thickness of border around tabs.
     float       TabMinWidthForCloseButton;  // Minimum width for close button to appear on an unselected tab when hovered. Set to 0.0f to always show when hovering, set to FLT_MAX to never show close button unless selected.
     float       TabBarBorderSize;           // Thickness of tab-bar separator, which takes on the tab active color to denote focus.
+    float       TableAngledHeadersAngle;    // Angle of angled headers (supported values range from -50.0f degrees to +50.0f degrees).
     ImGuiDir    ColorButtonPosition;        // Side of the color button in the ColorEdit4 widget (left/right). Defaults to ImGuiDir_Right.
     ImVec2      ButtonTextAlign;            // Alignment of button text when button is larger than text. Defaults to (0.5f, 0.5f) (centered).
     ImVec2      SelectableTextAlign;        // Alignment of selectable text. Defaults to (0.0f, 0.0f) (top-left aligned). It's generally important to keep this left-aligned if you want to lay multiple items on a same line.

imgui_demo.cpp

@@ -3949,6 +3949,7 @@ static void EditTableColumnsFlags(ImGuiTableColumnFlags* p_flags)
     ImGui::CheckboxFlags("_PreferSortDescending", p_flags, ImGuiTableColumnFlags_PreferSortDescending);
     ImGui::CheckboxFlags("_IndentEnable", p_flags, ImGuiTableColumnFlags_IndentEnable); ImGui::SameLine(); HelpMarker("Default for column 0");
     ImGui::CheckboxFlags("_IndentDisable", p_flags, ImGuiTableColumnFlags_IndentDisable); ImGui::SameLine(); HelpMarker("Default for column >0");
+    ImGui::CheckboxFlags("_AngledHeader", p_flags, ImGuiTableColumnFlags_AngledHeader);
 }
 
 static void ShowTableColumnsStatusFlags(ImGuiTableColumnFlags flags)
@@ -4695,8 +4696,14 @@ static void ShowDemoWindowTables()
         ImVec2 outer_size = ImVec2(0.0f, TEXT_BASE_HEIGHT * 9);
         if (ImGui::BeginTable("table_columns_flags", column_count, flags, outer_size))
         {
+            bool has_angled_header = false;
             for (int column = 0; column < column_count; column++)
+            {
+                has_angled_header |= (column_flags[column] & ImGuiTableColumnFlags_AngledHeader) != 0;
                 ImGui::TableSetupColumn(column_names[column], column_flags[column]);
+            }
+            if (has_angled_header)
+                ImGui::TableAngledHeadersRow();
             ImGui::TableHeadersRow();
             for (int column = 0; column < column_count; column++)
                 column_flags_out[column] = ImGui::TableGetColumnFlags(column);
@@ -5182,6 +5189,56 @@ static void ShowDemoWindowTables()
         ImGui::TreePop();
     }
 
+    // Demonstrate using ImGuiTableColumnFlags_AngledHeader flag to create angled headers
+    if (open_action != -1)
+        ImGui::SetNextItemOpen(open_action != 0);
+    IMGUI_DEMO_MARKER("Tables/Angled headers");
+    if (ImGui::TreeNode("Angled headers"))
+    {
+        const char* column_names[] = { "Track", "cabasa", "ride", "smash", "tom-hi", "tom-mid", "tom-low", "hihat-o", "hihat-c", "snare-s", "snare-c", "clap", "rim", "kick" };
+        const int columns_count = IM_ARRAYSIZE(column_names);
+        const int rows_count = 12;
+
+        static ImGuiTableFlags table_flags = ImGuiTableFlags_SizingFixedFit | ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY | ImGuiTableFlags_BordersOuter | ImGuiTableFlags_BordersInnerH | ImGuiTableFlags_Hideable | ImGuiTableFlags_Resizable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_HighlightHoveredColumn;
+        static bool bools[columns_count * rows_count] = {}; // Dummy storage selection storage
+        static int frozen_rows = 2;
+        ImGui::CheckboxFlags("_ScrollX", &table_flags, ImGuiTableFlags_ScrollX);
+        ImGui::CheckboxFlags("_ScrollY", &table_flags, ImGuiTableFlags_ScrollY);
+        ImGui::CheckboxFlags("_NoBordersInBody", &table_flags, ImGuiTableFlags_NoBordersInBody);
+        ImGui::CheckboxFlags("_HighlightHoveredColumn", &table_flags, ImGuiTableFlags_HighlightHoveredColumn);
+        ImGui::SetNextItemWidth(ImGui::GetFontSize() * 8);
+        ImGui::SliderInt("Frozen rows", &frozen_rows, 0, 2);
+
+        if (ImGui::BeginTable("table_angled_headers", columns_count, table_flags, ImVec2(0.0f, TEXT_BASE_HEIGHT * 12)))
+        {
+            ImGui::TableSetupColumn(column_names[0], ImGuiTableColumnFlags_NoHide | ImGuiTableColumnFlags_NoReorder);
+            for (int n = 1; n < columns_count; n++)
+                ImGui::TableSetupColumn(column_names[n], ImGuiTableColumnFlags_AngledHeader | ImGuiTableColumnFlags_WidthFixed);
+            ImGui::TableSetupScrollFreeze(0, frozen_rows);
+
+            ImGui::TableAngledHeadersRow(); // Draw angled headers for all columns with the ImGuiTableColumnFlags_AngledHeader flag.
+            ImGui::TableHeadersRow();       // Draw remaining headers and allow access to context-menu and other functions.
+            for (int row = 0; row < rows_count; row++)
+            {
+                ImGui::PushID(row);
+                ImGui::TableNextRow();
+                ImGui::TableSetColumnIndex(0);
+                ImGui::AlignTextToFramePadding();
+                ImGui::Text("Track %d", row);
+                for (int column = 1; column < columns_count; column++)
+                    if (ImGui::TableSetColumnIndex(column))
+                    {
+                        ImGui::PushID(column);
+                        ImGui::Checkbox("", &bools[row * columns_count + column]);
+                        ImGui::PopID();
+                    }
+                ImGui::PopID();
+            }
+            ImGui::EndTable();
+        }
+        ImGui::TreePop();
+    }
+
     // Demonstrate creating custom context menus inside columns, while playing it nice with context menus provided by TableHeadersRow()/TableHeader()
     if (open_action != -1)
         ImGui::SetNextItemOpen(open_action != 0);
@@ -5428,6 +5485,7 @@ static void ShowDemoWindowTables()
             | ImGuiTableFlags_RowBg | ImGuiTableFlags_Borders | ImGuiTableFlags_NoBordersInBody
             | ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY
             | ImGuiTableFlags_SizingFixedFit;
+        static ImGuiTableColumnFlags columns_base_flags = ImGuiTableColumnFlags_None;
 
         enum ContentsType { CT_Text, CT_Button, CT_SmallButton, CT_FillButton, CT_Selectable, CT_SelectableSpanRow };
         static int contents_type = CT_SelectableSpanRow;
@@ -5525,6 +5583,8 @@ static void ShowDemoWindowTables()
             {
                 ImGui::Checkbox("show_headers", &show_headers);
                 ImGui::CheckboxFlags("ImGuiTableFlags_HighlightHoveredColumn", &flags, ImGuiTableFlags_HighlightHoveredColumn);
+                ImGui::CheckboxFlags("ImGuiTableColumnFlags_AngledHeader", &columns_base_flags, ImGuiTableColumnFlags_AngledHeader);
+                ImGui::SameLine(); HelpMarker("Enable AngledHeader on all columns. Best enabled on selected narrow columns (see \"Angled headers\" section of the demo).");
                 ImGui::TreePop();
             }
 
@@ -5590,12 +5650,12 @@ static void ShowDemoWindowTables()
             // Declare columns
             // We use the "user_id" parameter of TableSetupColumn() to specify a user id that will be stored in the sort specifications.
             // This is so our sort function can identify a column given our own identifier. We could also identify them based on their index!
-            ImGui::TableSetupColumn("ID",           ImGuiTableColumnFlags_DefaultSort | ImGuiTableColumnFlags_WidthFixed | ImGuiTableColumnFlags_NoHide, 0.0f, MyItemColumnID_ID);
-            ImGui::TableSetupColumn("Name",         ImGuiTableColumnFlags_WidthFixed, 0.0f, MyItemColumnID_Name);
-            ImGui::TableSetupColumn("Action",       ImGuiTableColumnFlags_NoSort | ImGuiTableColumnFlags_WidthFixed, 0.0f, MyItemColumnID_Action);
-            ImGui::TableSetupColumn("Quantity",     ImGuiTableColumnFlags_PreferSortDescending, 0.0f, MyItemColumnID_Quantity);
-            ImGui::TableSetupColumn("Description",  (flags & ImGuiTableFlags_NoHostExtendX) ? 0 : ImGuiTableColumnFlags_WidthStretch, 0.0f, MyItemColumnID_Description);
-            ImGui::TableSetupColumn("Hidden",       ImGuiTableColumnFlags_DefaultHide | ImGuiTableColumnFlags_NoSort);
+            ImGui::TableSetupColumn("ID",           columns_base_flags | ImGuiTableColumnFlags_DefaultSort | ImGuiTableColumnFlags_WidthFixed | ImGuiTableColumnFlags_NoHide, 0.0f, MyItemColumnID_ID);
+            ImGui::TableSetupColumn("Name",         columns_base_flags | ImGuiTableColumnFlags_WidthFixed, 0.0f, MyItemColumnID_Name);
+            ImGui::TableSetupColumn("Action",       columns_base_flags | ImGuiTableColumnFlags_NoSort | ImGuiTableColumnFlags_WidthFixed, 0.0f, MyItemColumnID_Action);
+            ImGui::TableSetupColumn("Quantity",     columns_base_flags | ImGuiTableColumnFlags_PreferSortDescending, 0.0f, MyItemColumnID_Quantity);
+            ImGui::TableSetupColumn("Description",  columns_base_flags | ((flags & ImGuiTableFlags_NoHostExtendX) ? 0 : ImGuiTableColumnFlags_WidthStretch), 0.0f, MyItemColumnID_Description);
+            ImGui::TableSetupColumn("Hidden",       columns_base_flags |  ImGuiTableColumnFlags_DefaultHide | ImGuiTableColumnFlags_NoSort);
             ImGui::TableSetupScrollFreeze(freeze_cols, freeze_rows);
 
             // Sort our data if sort specs have been changed!
@@ -5614,6 +5674,8 @@ static void ShowDemoWindowTables()
             const bool sorts_specs_using_quantity = (ImGui::TableGetColumnFlags(3) & ImGuiTableColumnFlags_IsSorted) != 0;
 
             // Show headers
+            if (show_headers && (columns_base_flags & ImGuiTableColumnFlags_AngledHeader) != 0)
+                ImGui::TableAngledHeadersRow();
             if (show_headers)
                 ImGui::TableHeadersRow();
 
@@ -6400,7 +6462,6 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::SeparatorText("Main");
             ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
-            ImGui::SliderFloat2("CellPadding", (float*)&style.CellPadding, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat2("ItemSpacing", (float*)&style.ItemSpacing, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat2("ItemInnerSpacing", (float*)&style.ItemInnerSpacing, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat2("TouchExtraPadding", (float*)&style.TouchExtraPadding, 0.0f, 10.0f, "%.0f");
@@ -6425,6 +6486,10 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
             ImGui::SliderFloat("TabRounding", &style.TabRounding, 0.0f, 12.0f, "%.0f");
 
+            ImGui::SeparatorText("Tables");
+            ImGui::SliderFloat2("CellPadding", (float*)&style.CellPadding, 0.0f, 20.0f, "%.0f");
+            ImGui::SliderAngle("TableAngledHeadersAngle", &style.TableAngledHeadersAngle, -50.0f, +50.0f);
+
             ImGui::SeparatorText("Widgets");
             ImGui::SliderFloat2("WindowTitleAlign", (float*)&style.WindowTitleAlign, 0.0f, 1.0f, "%.2f");
             int window_menu_button_position = style.WindowMenuButtonPosition + 1;

imgui_draw.cpp

@@ -1989,6 +1989,14 @@ void ImGui::ShadeVertsLinearUV(ImDrawList* draw_list, int vert_start_idx, int ve
     }
 }
 
+void ImGui::ShadeVertsTransformPos(ImDrawList* draw_list, int vert_start_idx, int vert_end_idx, const ImVec2& pivot_in, float cos_a, float sin_a, const ImVec2& pivot_out)
+{
+    ImDrawVert* vert_start = draw_list->VtxBuffer.Data + vert_start_idx;
+    ImDrawVert* vert_end = draw_list->VtxBuffer.Data + vert_end_idx;
+    for (ImDrawVert* vertex = vert_start; vertex < vert_end; ++vertex)
+        vertex->pos = ImRotate(vertex->pos- pivot_in, cos_a, sin_a) + pivot_out;
+}
+
 //-----------------------------------------------------------------------------
 // [SECTION] ImFontConfig
 //-----------------------------------------------------------------------------