1 files changed, 94 insertions, 2 deletions

diff --git a/generic/tkTextDisp.c b/generic/tkTextDisp.c
index 6036222..d8a17a9 100644
--- a/generic/tkTextDisp.c
+++ b/generic/tkTextDisp.c
@@ -590,6 +590,7 @@ static int		TextGetScrollInfoObj(Tcl_Interp *interp,
 			    Tcl_Obj *CONST objv[], double *dblPtr,
 			    int *intPtr);
 static void		AsyncUpdateLineMetrics(ClientData clientData);
+static void		GenerateWidgetViewSyncEvent(TkText *textPtr, Bool InSync);
 static void		AsyncUpdateYScrollbar(ClientData clientData);
 static int              IsStartOfNotMergedLine(TkText *textPtr,
                             CONST TkTextIndex *indexPtr);
@@ -2920,6 +2921,8 @@ AsyncUpdateLineMetrics(
     lineNum = TkTextUpdateLineMetrics(textPtr, lineNum,
 	    dInfoPtr->lastMetricUpdateLine, 256);
 
+    dInfoPtr->currentMetricUpdateLine = lineNum;
+
     if (tkTextDebug) {
 	char buffer[2 * TCL_INTEGER_SPACE + 1];
 
@@ -2937,16 +2940,37 @@ AsyncUpdateLineMetrics(
 	/*
 	 * We have looped over all lines, so we're done. We must release our
 	 * refCount on the widget (the timer token was already set to NULL
-	 * above).
+	 * above). If there is a registered aftersync command, run that first.
 	 */
 
+	if (textPtr->afterSyncCmd != NULL) {
+	    int code;
+	    Tcl_Preserve((ClientData)textPtr->interp);
+	    code = Tcl_EvalObjEx(textPtr->interp, textPtr->afterSyncCmd, TCL_EVAL_GLOBAL);
+	    if (code != TCL_OK && code != TCL_CONTINUE
+			&& code != TCL_BREAK) {
+		    Tcl_AddErrorInfo(textPtr->interp, "\n    (text sync)");
+		    Tcl_BackgroundError(textPtr->interp);
+	    }
+	    Tcl_Release((ClientData)textPtr->interp);
+	    Tcl_DecrRefCount(textPtr->afterSyncCmd);
+	    textPtr->afterSyncCmd = 0;
+	}
+
+        /*
+         * Fire the <<WidgetViewSync>> event since the widget view is in sync
+         * with its internal data (actually it will be after the next trip
+         * through the event loop, because the widget redraws at idle-time).
+         */
+
+        GenerateWidgetViewSyncEvent(textPtr, 1);
+
 	textPtr->refCount--;
 	if (textPtr->refCount == 0) {
 	    ckfree((char *) textPtr);
 	}
 	return;
     }
-    dInfoPtr->currentMetricUpdateLine = lineNum;
 
     /*
      * Re-arm the timer. We already have a refCount on the text widget so no
@@ -2960,6 +2984,45 @@ AsyncUpdateLineMetrics(
 /*
  *----------------------------------------------------------------------
  *
+ * GenerateWidgetViewSyncEvent --
+ *
+ *      Send the <<WidgetViewSync>> event related to the text widget
+ *      line metrics asynchronous update.
+ *      This is equivalent to:
+ *         event generate $textWidget <<WidgetViewSync>> -detail $s
+ *      where $s is the sync status: true (when the widget view is in
+ *      sync with its internal data) or false (when it is not).
+ *
+ * Results:
+ *      None
+ *
+ * Side effects:
+ *      If corresponding bindings are present, they will trigger.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+GenerateWidgetViewSyncEvent(
+    TkText *textPtr,		/* Information about text widget. */
+    Bool InSync)                /* True if in sync, false otherwise */
+{
+    union {XEvent general; XVirtualEvent virtual;} event;
+
+    memset(&event, 0, sizeof(event));
+    event.general.xany.type = VirtualEvent;
+    event.general.xany.serial = NextRequest(Tk_Display(textPtr->tkwin));
+    event.general.xany.send_event = False;
+    event.general.xany.window = Tk_WindowId(textPtr->tkwin);
+    event.general.xany.display = Tk_Display(textPtr->tkwin);
+    event.virtual.name = Tk_GetUid("WidgetViewSync");
+    event.virtual.user_data = Tcl_NewBooleanObj(InSync);
+    Tk_HandleEvent(&event.general);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TkTextUpdateLineMetrics --
  *
  *	This function updates the pixel height calculations of a range of
@@ -3336,6 +3399,7 @@ TextInvalidateLineMetrics(
 	textPtr->refCount++;
 	dInfoPtr->lineUpdateTimer = Tcl_CreateTimerHandler(1,
 		AsyncUpdateLineMetrics, (ClientData) textPtr);
+        GenerateWidgetViewSyncEvent(textPtr, 0);
     }
 }
 
@@ -5040,6 +5104,7 @@ TkTextRelayoutWindow(
 	    textPtr->refCount++;
 	    dInfoPtr->lineUpdateTimer = Tcl_CreateTimerHandler(1,
 		    AsyncUpdateLineMetrics, (ClientData) textPtr);
+            GenerateWidgetViewSyncEvent(textPtr, 0);
 	}
     }
 }
@@ -6034,6 +6099,33 @@ TkTextYviewCmd(
 /*
  *--------------------------------------------------------------
  *
+ * TkTextPendingsync --
+ *
+ *	This function computes how many lines are not up-to-date regarding
+ *	asynchronous height calculations.
+ *
+ * Results:
+ *	Returns a positive integer corresponding to the number of lines for
+ *	which the height is outdated.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextPendingsync(
+    TkText *textPtr)		/* Information about text widget. */
+{
+    TextDInfo *dInfoPtr = textPtr->dInfoPtr;
+
+    return (dInfoPtr->lastMetricUpdateLine - dInfoPtr->currentMetricUpdateLine);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
  * TkTextScanCmd --
  *
  *	This function is invoked to process the "scan" option for the widget