TextSelect: Ctrl+A selects the selection's container, widening on each press; copy and select-all keys are configurable chords (TextSelectSetCopyShortcut(), TextSelectSetSelectAllShortcut()).

docs/CHANGELOG.txt

@@ -102,6 +102,9 @@ Other Changes:
   text selection/copy of any displayed text without changes to widget code.
 - Misc: added misc/text_select/ extension using the hook above: mouse selection
   (click/drag, word, line, block), highlight, and Ctrl+C/Cmd+C copy of any drawn text.
+  Ctrl+A/Cmd+A selects the selection's container, widening on each press (table ->
+  window -> parent window). Keys are configurable with `TextSelectSetCopyShortcut()`
+  and `TextSelectSetSelectAllShortcut()`.
 - ImVec2: added a check for cases where a custom `IM_VEC2_CLASS_EXTRA` macro
   adds an extra `operator=` to ImVec2. This isn't supported but should not
   be needed as you should have a constructor to convert from your type to ImVec2.

misc/text_select/imgui_text_select.cpp

@@ -55,6 +55,8 @@ struct ImGuiTextSelectState
     bool            Enabled = true;
     ImGuiTextSelectCopyFeedbackCallback CopyFeedback = NULL;
     void*           CopyFeedbackUserData = NULL;
+    ImGuiKeyChord   SelectAllChords[2] = { ImGuiMod_Ctrl | ImGuiKey_A, 0 };
+    ImGuiKeyChord   CopyChords[2] = { ImGuiMod_Ctrl | ImGuiKey_C, ImGuiMod_Ctrl | ImGuiKey_Insert };
     double          FlashStartTime = -1.0;  // Built-in copy feedback: the highlight turns opaque and fades back
     bool            Delimiters[128] = {};
 
@@ -855,6 +857,39 @@ static const ImGuiTextSelectRange* TextSelectExtendContainer(ImGuiTextSelectStat
     return (st->Dragging && has_anchor) ? &st->Anchor : NULL;
 }
 
+// Selects all of the anchor's container; when a previous call already did, widens it first: a table to its window, a
+// child window to its parent. A drag is clamped to its container, so only this leaves the anchor at -far_away.
+static void TextSelectSelectAllInContainer(ImGuiTextSelectState* st)
+{
+    const float far_away = 1e8f;
+    ImGuiTextSelectRange c = st->Anchor;
+    if (c.Begin.x == -far_away && st->Focus.End.x == far_away && !c.MenuBar)
+    {
+        if (c.TableId != 0)
+        {
+            c.TableId = 0;
+        }
+        else if (c.Window != c.Window->RootWindow && c.Window->ParentWindow != NULL)
+        {
+            c.Window = c.Window->ParentWindow;
+            c.WindowId = c.Window->ID;
+        }
+    }
+    c.Begin = c.End = ImVec2(-far_away, -far_away);
+    st->Anchor = c;
+    c.Begin = c.End = ImVec2(far_away, far_away);
+    st->Focus = c;
+    st->Block = false;
+}
+
+static ImGuiKey TextSelectChordPressed(const ImGuiKeyChord (&chords)[2])
+{
+    for (ImGuiKeyChord chord : chords)
+        if (chord != 0 && ImGui::IsKeyChordPressed(chord))
+            return (ImGuiKey)(chord & ~ImGuiMod_Mask_);
+    return ImGuiKey_None;
+}
+
 static void TextSelectNewFrame(ImGuiContext* ctx, ImGuiContextHook* hook)
 {
     ImGuiTextSelectState* st = (ImGuiTextSelectState*)hook->UserData;
@@ -912,6 +947,19 @@ static void TextSelectNewFrame(ImGuiContext* ctx, ImGuiContextHook* hook)
     st->ProbeTextDistEm = FLT_MAX;
     st->ProbeGlyphItemId = 0;
 
+    const ImGuiKey select_all_key = TextSelectChordPressed(st->SelectAllChords);
+    if (select_all_key != ImGuiKey_None && st->RootWindow != NULL && !io.WantTextInput)
+    {
+        const bool owns_window = (g.HoveredWindow != NULL && g.HoveredWindow->RootWindow == st->RootWindow) || (g.NavWindow != NULL && g.NavWindow->RootWindow == st->RootWindow);
+        if (owns_window)
+        {
+            TextSelectSelectAllInContainer(st);
+            TextSelectResolve(st);
+            // Nobody else acts on this select-all key press
+            ImGui::SetKeyOwner(select_all_key, ImGuiKeyOwner_Any, ImGuiInputFlags_LockThisFrame);
+        }
+    }
+
     if (st->CopyRequested)
     {
         st->CopyRequested = false;
@@ -922,7 +970,8 @@ static void TextSelectNewFrame(ImGuiContext* ctx, ImGuiContextHook* hook)
         }
     }
     st->RequestedCopyText.clear();
-    if (!(io.KeyCtrl || io.KeySuper) || !(ImGui::IsKeyPressed(ImGuiKey_C, false) || ImGui::IsKeyPressed(ImGuiKey_Insert, false)))
+    const ImGuiKey copy_key = TextSelectChordPressed(st->CopyChords);
+    if (copy_key == ImGuiKey_None)
         return;
     if (!st->Active)
     {
@@ -936,8 +985,7 @@ static void TextSelectNewFrame(ImGuiContext* ctx, ImGuiContextHook* hook)
     {
         TextSelectBeginCopy(st);
         // Nobody else acts on this copy key press
-        ImGui::SetKeyOwner(ImGuiKey_C, ImGuiKeyOwner_Any, ImGuiInputFlags_LockThisFrame);
-        ImGui::SetKeyOwner(ImGuiKey_Insert, ImGuiKeyOwner_Any, ImGuiInputFlags_LockThisFrame);
+        ImGui::SetKeyOwner(copy_key, ImGuiKeyOwner_Any, ImGuiInputFlags_LockThisFrame);
     }
 }
 
@@ -1226,6 +1274,24 @@ void ImGui::TextSelectSetCopyFeedbackCallback(ImGuiTextSelectCopyFeedbackCallbac
     }
 }
 
+void ImGui::TextSelectSetCopyShortcut(ImGuiKeyChord key_chord, ImGuiKeyChord alt_key_chord)
+{
+    if (ImGuiTextSelectState* st = TextSelectGetState())
+    {
+        st->CopyChords[0] = key_chord;
+        st->CopyChords[1] = alt_key_chord;
+    }
+}
+
+void ImGui::TextSelectSetSelectAllShortcut(ImGuiKeyChord key_chord, ImGuiKeyChord alt_key_chord)
+{
+    if (ImGuiTextSelectState* st = TextSelectGetState())
+    {
+        st->SelectAllChords[0] = key_chord;
+        st->SelectAllChords[1] = alt_key_chord;
+    }
+}
+
 void ImGui::TextSelectSetWordDelimiters(const char* delimiters)
 {
     if (ImGuiTextSelectState* st = TextSelectGetState())

misc/text_select/imgui_text_select.h

@@ -13,10 +13,13 @@
 //   the first and last selected glyphs. Child windows inside the container take part only when they overlap the
 //   rectangle spanned by the two ends (selecting in one of two side-by-side children leaves the other out).
 // - A word is a run of word characters, or a run of delimiter characters (see TextSelectSetWordDelimiters()).
-// - Ctrl+C (Cmd+C on macOS) or Ctrl+Insert copies the selection in reading order: lines from top to bottom,
+// - Ctrl+C (Cmd+C on macOS) or Ctrl+Insert (see TextSelectSetCopyShortcut()) copies the selection in reading order: lines from top to bottom,
 //   fragments on a line from left to right, wide gaps (e.g. table columns) as tabs, soft-wrapped lines joined by a space
 //   (or as given to TextSelectMarkSoftWrap()). The container's rows and columns scrolled out of view are submitted for
 //   that one frame (through ImGuiListClipper and tables' box-select unclip support) and copied; hidden columns are not.
+// - Ctrl+A (Cmd+A on macOS), with a caret or selection in the hovered or focused window, selects everything in its
+//   container; each further press widens it: a table to its window, a child window to its parent, up to the root.
+//   TextSelectSetSelectAllShortcut() changes or disables the key.
 // - Escape, or a click on a widget other than the container's scrollbars, clears the selection.
 // - When io.ConfigWindowsMoveFromTitleBarOnly is off, a click on background farther than the width of an 'M' (in the
 //   text's font) from any text on its line clears the selection and a drag there moves the window; closer, it selects.
@@ -58,6 +61,11 @@ namespace ImGui
     void        TextSelectSetCopyFeedbackCallback(ImGuiTextSelectCopyFeedbackCallback callback, void* user_data);
     // ASCII characters that end a word, besides blanks. Other characters, including all non-ASCII, are word characters.
     void        TextSelectSetWordDelimiters(const char* delimiters);
+    // Default ImGuiMod_Ctrl | ImGuiKey_A (Cmd+A on macOS with io.ConfigMacOSXBehaviors). Either chord selects; 0 disables
+    // it, e.g. (ImGuiMod_Ctrl | ImGuiKey_A, ImGuiMod_Super | ImGuiKey_A) also accepts the other modifier.
+    // Default ImGuiMod_Ctrl | ImGuiKey_C and ImGuiMod_Ctrl | ImGuiKey_Insert. Either chord copies; 0 disables it.
+    void        TextSelectSetCopyShortcut(ImGuiKeyChord key_chord, ImGuiKeyChord alt_key_chord = 0);
+    void        TextSelectSetSelectAllShortcut(ImGuiKeyChord key_chord, ImGuiKeyChord alt_key_chord = 0);
 
     // Text drawn in between is ignored (as ImGuiItemFlags_NoTextSelect), and clicks on that stretch of the current
     // window, from the cursor at Push to the cursor at Pop, do not set the anchor.
@@ -75,7 +83,7 @@ namespace ImGui
     // The next text drawn in the current window continues the previous line (a soft wrap done by the caller):
     // copies join the two with join (a static string, "" for a word cut in two) instead of a newline.
     void        TextSelectMarkSoftWrap(const char* join = " ");
-    // Selects everything in the current window and its child windows (e.g. on Ctrl+A in a text view).
+    // Selects everything in the current window and its child windows, e.g. from a "Select all" menu item.
     void        TextSelectSelectAll();
     // Selects the text inside a rectangle of the current window and copies it on the next frame, with the usual copy
     // feedback, e.g. from a click handler. copy_text, when given, is what reaches the clipboard instead.