Merged implementation of TIP #449 - [text] undo/redo to Return Range of Characters - following acceptation by vote of the TCT

5 files changed, 264 insertions, 6 deletions

diff --git a/doc/text.n b/doc/text.n
index 9bbe8bc..860fa30 100644
--- a/doc/text.n
+++ b/doc/text.n
@@ -1307,8 +1307,9 @@ of the widget to \fIboolean\fR.
 \fIpathName \fBedit redo\fR
 .
 When the \fB\-undo\fR option is true, reapplies the last undone edits provided
-no other edits were done since then. Generates an error when the redo stack is
-empty. Does nothing when the \fB\-undo\fR option is false.
+no other edits were done since then, and returns a list of indices indicating
+what ranges were changed by the redo operation. Generates an error when the
+redo stack is empty. Does nothing when the \fB\-undo\fR option is false.
 .TP
 \fIpathName \fBedit reset\fR
 .
@@ -1321,9 +1322,10 @@ Inserts a separator (boundary) on the undo stack. Does nothing when the
 .TP
 \fIpathName \fBedit undo\fR
 .
-Undoes the last edit action when the \fB\-undo\fR option is true. An edit
-action is defined as all the insert and delete commands that are recorded on
-the undo stack in between two separators. Generates an error when the undo
+Undoes the last edit action when the \fB\-undo\fR option is true, and returns a
+list of indices indicating what ranges were changed by the undo operation. An
+edit action is defined as all the insert and delete commands that are recorded
+on the undo stack in between two separators. Generates an error when the undo
 stack is empty. Does nothing when the \fB\-undo\fR option is false.
 .RE
 .TP
diff --git a/generic/tkText.c b/generic/tkText.c
index bea4c62..ea11af1 100644
--- a/generic/tkText.c
+++ b/generic/tkText.c
@@ -2774,6 +2774,9 @@ TextPushUndoAction(
 {
     TkUndoSubAtom *iAtom, *dAtom;
     int canUndo, canRedo;
+    char lMarkName[20] = "tk::undoMarkL";
+    char rMarkName[20] = "tk::undoMarkR";
+    char stringUndoMarkId[7] = "";
 
     /*
      * Create the helpers.
@@ -2784,6 +2787,10 @@ TextPushUndoAction(
     Tcl_Obj *markSet2InsertObj = NULL;
     Tcl_Obj *insertCmdObj = Tcl_NewObj();
     Tcl_Obj *deleteCmdObj = Tcl_NewObj();
+    Tcl_Obj *markSetLUndoMarkCmdObj = Tcl_NewObj();
+    Tcl_Obj *markSetRUndoMarkCmdObj = NULL;
+    Tcl_Obj *markGravityLUndoMarkCmdObj = Tcl_NewObj();
+    Tcl_Obj *markGravityRUndoMarkCmdObj = NULL;
 
     /*
      * Get the index positions.
@@ -2833,6 +2840,40 @@ TextPushUndoAction(
     Tcl_ListObjAppendElement(NULL, deleteCmdObj, index1Obj);
     Tcl_ListObjAppendElement(NULL, deleteCmdObj, index2Obj);
 
+    Tcl_ListObjAppendElement(NULL, markSetLUndoMarkCmdObj,
+	    Tcl_NewStringObj(Tk_PathName(textPtr->tkwin), -1));
+    Tcl_ListObjAppendElement(NULL, markSetLUndoMarkCmdObj,
+	    Tcl_NewStringObj("mark", 4));
+    Tcl_ListObjAppendElement(NULL, markSetLUndoMarkCmdObj,
+	    Tcl_NewStringObj("set", 3));
+    markSetRUndoMarkCmdObj = Tcl_DuplicateObj(markSetLUndoMarkCmdObj);
+    textPtr->sharedTextPtr->undoMarkId++;
+    sprintf(stringUndoMarkId, "%d", textPtr->sharedTextPtr->undoMarkId);
+    strcat(lMarkName, stringUndoMarkId);
+    strcat(rMarkName, stringUndoMarkId);
+    Tcl_ListObjAppendElement(NULL, markSetLUndoMarkCmdObj,
+	    Tcl_NewStringObj(lMarkName, -1));
+    Tcl_ListObjAppendElement(NULL, markSetRUndoMarkCmdObj,
+	    Tcl_NewStringObj(rMarkName, -1));
+    Tcl_ListObjAppendElement(NULL, markSetLUndoMarkCmdObj, index1Obj);
+    Tcl_ListObjAppendElement(NULL, markSetRUndoMarkCmdObj, index2Obj);
+
+    Tcl_ListObjAppendElement(NULL, markGravityLUndoMarkCmdObj,
+	    Tcl_NewStringObj(Tk_PathName(textPtr->tkwin), -1));
+    Tcl_ListObjAppendElement(NULL, markGravityLUndoMarkCmdObj,
+	    Tcl_NewStringObj("mark", 4));
+    Tcl_ListObjAppendElement(NULL, markGravityLUndoMarkCmdObj,
+	    Tcl_NewStringObj("gravity", 7));
+    markGravityRUndoMarkCmdObj = Tcl_DuplicateObj(markGravityLUndoMarkCmdObj);
+    Tcl_ListObjAppendElement(NULL, markGravityLUndoMarkCmdObj,
+	    Tcl_NewStringObj(lMarkName, -1));
+    Tcl_ListObjAppendElement(NULL, markGravityRUndoMarkCmdObj,
+	    Tcl_NewStringObj(rMarkName, -1));
+    Tcl_ListObjAppendElement(NULL, markGravityLUndoMarkCmdObj,
+            Tcl_NewStringObj("left", 4));
+    Tcl_ListObjAppendElement(NULL, markGravityRUndoMarkCmdObj,
+            Tcl_NewStringObj("right", 5));
+
     /*
      * Note: we don't wish to use textPtr->widgetCmd in these callbacks
      * because if we delete the textPtr, but peers still exist, we will then
@@ -2850,11 +2891,19 @@ TextPushUndoAction(
 	    insertCmdObj, NULL);
     TkUndoMakeCmdSubAtom(NULL, markSet2InsertObj, iAtom);
     TkUndoMakeCmdSubAtom(NULL, seeInsertObj, iAtom);
+    TkUndoMakeCmdSubAtom(NULL, markSetLUndoMarkCmdObj, iAtom);
+    TkUndoMakeCmdSubAtom(NULL, markSetRUndoMarkCmdObj, iAtom);
+    TkUndoMakeCmdSubAtom(NULL, markGravityLUndoMarkCmdObj, iAtom);
+    TkUndoMakeCmdSubAtom(NULL, markGravityRUndoMarkCmdObj, iAtom);
 
     dAtom = TkUndoMakeSubAtom(&TextUndoRedoCallback, textPtr->sharedTextPtr,
 	    deleteCmdObj, NULL);
     TkUndoMakeCmdSubAtom(NULL, markSet1InsertObj, dAtom);
     TkUndoMakeCmdSubAtom(NULL, seeInsertObj, dAtom);
+    TkUndoMakeCmdSubAtom(NULL, markSetLUndoMarkCmdObj, dAtom);
+    TkUndoMakeCmdSubAtom(NULL, markSetRUndoMarkCmdObj, dAtom);
+    TkUndoMakeCmdSubAtom(NULL, markGravityLUndoMarkCmdObj, dAtom);
+    TkUndoMakeCmdSubAtom(NULL, markGravityRUndoMarkCmdObj, dAtom);
 
     Tcl_DecrRefCount(seeInsertObj);
     Tcl_DecrRefCount(index1Obj);
@@ -5069,6 +5118,8 @@ TextEditUndo(
     TkText *textPtr)		/* Overall information about text widget. */
 {
     int status;
+    Tcl_Obj *cmdObj;
+    int code;
 
     if (!textPtr->sharedTextPtr->undo) {
 	return TCL_OK;
@@ -5092,6 +5143,22 @@ TextEditUndo(
     }
     textPtr->sharedTextPtr->undo = 1;
 
+    /*
+     * Convert undo/redo temporary marks set by TkUndoRevert() into
+     * indices left in the interp result.
+     */
+
+    cmdObj = Tcl_ObjPrintf("::tk::TextUndoRedoProcessMarks %s",
+            Tk_PathName(textPtr->tkwin));
+    Tcl_IncrRefCount(cmdObj);
+    code = Tcl_EvalObjEx(textPtr->interp, cmdObj, TCL_EVAL_GLOBAL);
+    if (code != TCL_OK) {
+        Tcl_AddErrorInfo(textPtr->interp,
+                "\n    (on undoing)");
+        Tcl_BackgroundException(textPtr->interp, code);
+    }
+    Tcl_DecrRefCount(cmdObj);
+
     return status;
 }
 
@@ -5117,6 +5184,8 @@ TextEditRedo(
     TkText *textPtr)		/* Overall information about text widget. */
 {
     int status;
+    Tcl_Obj *cmdObj;
+    int code;
 
     if (!textPtr->sharedTextPtr->undo) {
 	return TCL_OK;
@@ -5139,6 +5208,23 @@ TextEditRedo(
 	textPtr->sharedTextPtr->dirtyMode = TK_TEXT_DIRTY_NORMAL;
     }
     textPtr->sharedTextPtr->undo = 1;
+
+    /*
+     * Convert undo/redo temporary marks set by TkUndoApply() into
+     * indices left in the interp result.
+     */
+
+    cmdObj = Tcl_ObjPrintf("::tk::TextUndoRedoProcessMarks %s",
+            Tk_PathName(textPtr->tkwin));
+    Tcl_IncrRefCount(cmdObj);
+    code = Tcl_EvalObjEx(textPtr->interp, cmdObj, TCL_EVAL_GLOBAL);
+    if (code != TCL_OK) {
+        Tcl_AddErrorInfo(textPtr->interp,
+                "\n    (on undoing)");
+        Tcl_BackgroundException(textPtr->interp, code);
+    }
+    Tcl_DecrRefCount(cmdObj);
+
     return status;
 }
 
diff --git a/generic/tkText.h b/generic/tkText.h
index 5d88784..430c96b 100644
--- a/generic/tkText.h
+++ b/generic/tkText.h
@@ -580,6 +580,8 @@ typedef struct TkSharedText {
 				 * statements. */
     int autoSeparators;		/* Non-zero means the separators will be
 				 * inserted automatically. */
+    int undoMarkId;             /* Counts undo marks temporarily used during
+                                   undo and redo operations. */
     int isDirty;		/* Flag indicating the 'dirtyness' of the
 				 * text widget. If the flag is not zero,
 				 * unsaved modifications have been applied to
diff --git a/library/text.tcl b/library/text.tcl
index 2bf1b2b..02a8939 100644
--- a/library/text.tcl
+++ b/library/text.tcl
@@ -1202,3 +1202,99 @@ proc ::tk::TextScanDrag {w x y} {
 	$w scan dragto $x $y
     }
 }
+
+# ::tk::TextUndoRedoProcessMarks --
+#
+# This proc is executed after an undo or redo action.
+# It processes the list of undo/redo marks temporarily set in the
+# text widget to positions delimiting where changes happened, and
+# returns a flat list of ranges. The temporary marks are removed
+# from the text widget.
+#
+# Arguments:
+# w -	The text widget
+
+proc ::tk::TextUndoRedoProcessMarks {w} {
+    set indices {}
+    set undoMarks {}
+
+    # only consider the temporary marks set by an undo/redo action
+    foreach mark [$w mark names] {
+        if {[string range $mark 0 11] eq "tk::undoMark"} {
+            lappend undoMarks $mark
+        }
+    }
+
+    # transform marks into indices
+    # the number of undo/redo marks is always even, each right mark
+    # completes a left mark to give a range
+    # this is true because:
+    #   - undo/redo only deals with insertions and deletions of text
+    #   - insertions may move marks but not delete them
+    #   - when deleting text, marks located inside the deleted range
+    #     are not erased but moved to the start of the deletion range
+    #         . this is done in TkBTreeDeleteIndexRange ("This segment
+    #           refuses to die...")
+    #         . because MarkDeleteProc does nothing else than returning
+    #           a value indicating that marks are not deleted by this
+    #           deleteProc
+    #         . mark deletion rather happen through [.text mark unset xxx]
+    #           which was not used _up to this point of the code_ (it
+    #           is a bit later just before exiting the present proc)
+    set nUndoMarks [llength $undoMarks]
+    set n [expr {$nUndoMarks / 2}]
+    set undoMarks [lsort -dictionary $undoMarks]
+    set Lmarks [lrange $undoMarks 0 [expr {$n - 1}]]
+    set Rmarks [lrange $undoMarks $n [llength $undoMarks]]
+    foreach Lmark $Lmarks Rmark $Rmarks {
+        lappend indices [$w index $Lmark] [$w index $Rmark]
+        $w mark unset $Lmark $Rmark
+    }
+
+    # process ranges to:
+    #   - remove those already fully included in another range
+    #   - merge overlapping ranges
+    set ind [lsort -dictionary -stride 2 $indices]
+    set indices {}
+
+    for {set i 0} {$i < $nUndoMarks} {incr i 2} {
+        set il1 [lindex $ind $i]
+        set ir1 [lindex $ind [expr {$i + 1}]]
+        lappend indices $il1 $ir1
+ 
+        for {set j [expr {$i + 2}]} {$j < $nUndoMarks} {incr j 2} {
+            set il2 [lindex $ind $j]
+            set ir2 [lindex $ind [expr {$j + 1}]]
+ 
+            if {[$w compare $il2 > $ir1]} {
+                # second range starts after the end of first range
+                # -> further second ranges do not need to be considered
+                #    because ranges were sorted by increasing first index
+                set j $nUndoMarks
+ 
+            } else {
+                if {[$w compare $ir2 > $ir1]} {
+                    # second range overlaps first range
+                    # -> merge them into a single range
+                    set indices [lreplace $indices end-1 end]
+                    lappend indices $il1 $ir2
+
+                } else {
+                    # second range is fully included in first range
+                    # -> ignore it
+
+                }
+                # in both cases above, the second range shall be
+                # trimmed out from the list of ranges
+                set ind [lreplace $ind $j [expr {$j + 1}]]
+                incr j -2
+                incr nUndoMarks -2
+ 
+            }
+
+        }
+
+    }
+
+    return $indices
+}
diff --git a/tests/text.test b/tests/text.test
index 8723d3d..b4a7a2b 100644
--- a/tests/text.test
+++ b/tests/text.test
@@ -1458,7 +1458,19 @@ Line 7"
     rename .t {}
     rename test.t .t
     destroy .t
-} -result {{edit undo} {delete 2.1 2.4} {mark set insert 2.1} {see insert} {insert 2.1 ef} {mark set insert 2.3} {see insert}}
+} -result [list {edit undo} {delete 2.1 2.4} {mark set insert 2.1} {see insert} \
+                {mark set tk::undoMarkL3 2.1} {mark set tk::undoMarkR3 2.4} \
+                {mark gravity tk::undoMarkL3 left} {mark gravity tk::undoMarkR3 right} \
+                {insert 2.1 ef} {mark set insert 2.3} {see insert} \
+                {mark set tk::undoMarkL2 2.1} {mark set tk::undoMarkR2 2.3} \
+                {mark gravity tk::undoMarkL2 left} {mark gravity tk::undoMarkR2 right} \
+                {mark names} \
+                {index tk::undoMarkL2} {index tk::undoMarkR2} \
+                {mark unset tk::undoMarkL2 tk::undoMarkR2} \
+                {index tk::undoMarkL3} {index tk::undoMarkR3} \
+                {mark unset tk::undoMarkL3 tk::undoMarkR3} \
+                {compare 2.1 > 2.3} {compare 2.6 > 2.3} ]
+
 test text-8.23 {TextWidgetCmd procedure, "replace" option with undo} -setup {
     text .t
 } -body {
@@ -6577,6 +6589,66 @@ test text-27.25 {<<UndoStack>> virtual event} -setup {
 } -cleanup {
     destroy .t
 } -result {0 0 1 2 3 4 4 5 6 6 7 8 8 9}
+test text-27.26 {edit undo and edit redo return ranges} -setup {
+    destroy .t
+    set res {}
+} -body {
+    text .t -undo true -autoseparators false
+    .t insert end "Hello "
+    .t edit separator
+    .t insert end "World!\n"
+    .t insert 1.6 "GREAT "
+    .t insert end "Another edit here!!"
+    lappend res [.t edit undo]
+    lappend res [.t edit redo]
+    .t edit separator
+    .t delete 1.6
+    .t delete 1.9 1.10
+    .t insert 1.9 L
+    lappend res [.t edit undo]
+    lappend res [.t edit redo]
+    .t replace 1.6 1.10 Tcl/Tk
+    .t replace 2.8 2.12 "one bites the dust"
+    lappend res [.t edit undo]
+    lappend res [.t edit redo]
+} -cleanup {
+    destroy .t
+} -result [list {1.6 2.0}           \
+                {1.6 2.19}          \
+                {1.6 1.7 1.10 1.12} \
+                {1.6 1.7 1.9 1.11}  \
+                {1.6 1.16 2.8 2.19} \
+                {1.6 1.16 2.8 2.30} ]
+test text-27.27 {edit undo and edit redo return ranges} -setup {
+    destroy .t
+    set res {}
+} -body {
+    text .t -undo true -autoseparators false
+    for {set i 3} {$i >= 1} {incr i -1} {
+        .t insert 1.0 "Line $i\n"
+    }
+    lappend res [.t edit undo]
+    lappend res [.t edit redo]
+} -cleanup {
+    destroy .t
+} -result [list {1.0 2.0} \
+                {1.0 4.0} ]
+test text-27.28 {edit undo and edit redo do not leave \
+                 spurious temporary marks behind them} -setup {
+    destroy .t
+    set res {}
+} -body {
+    pack [text .t -undo true -autoseparators false]
+    .t insert end "Hello World.\n"
+    .t edit separator
+    .t insert end "Again hello.\n"
+    .t edit undo
+    lappend res [lsearch [.t mark names] tk::undoMark*]
+    .t edit redo
+    lappend res [lsearch [.t mark names] tk::undoMark*]
+} -cleanup {
+    destroy .t
+} -result [list -1 -1]
 
 
 test text-28.1 {bug fix - 624372, ControlUtfProc long lines} -body {