it turns out edit_redraw() is needed after all when doing

PageUp/PageDown; revert all the movement code and edit_scroll() changes
except for added comments and edit_scroll() simplifications


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2860 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

@@ -34,10 +34,6 @@ CVS code -
 	  (DLR)
 	- Consistently make the flags global and any variables used to
 	  hold it longs. (DLR)
-	- Tweak the movement routines to redraw all necessary lines
-	  instead of relying on edit_redraw().  Changes to
-	  do_page_up(), do_page_down(), do_up(), do_down(), and
-	  edit_scroll(). (DLR)
 	- Consistently make the fg and bg colortype struct entries and
 	  any variables used to hold them shorts.  Changes to
 	  do_colorinit() (renamed color_init()), color_to_int() (renamed
@@ -101,6 +97,8 @@ CVS code -
 	- Blank out last_replace properly again just before displaying
 	  the "Replace" prompt. (DLR, found by Mike Frysinger)
 - winio.c:
+  edit_scroll()
+	- Clean up and simplify. (DLR)
   do_statusbar_next_word()
 	- Rework to be more like do_statusbar_prev_word(), to avoid a
 	  potential problem if we start at the end of a line. (DLR)

src/move.c

@@ -100,6 +100,9 @@ void do_end(void)
 
 void do_page_up(void)
 {
+    const filestruct *current_save = openfile->current;
+    size_t pww_save = openfile->placewewant;
+
 #ifndef DISABLE_WRAPPING
     wrap_reset();
 #endif
@@ -108,22 +111,21 @@ void do_page_up(void)
      * and put the cursor at the beginning of the line. */
     if (openfile->edittop == openfile->fileage) {
 	openfile->current = openfile->fileage;
-	openfile->current_x = 0;
 	openfile->placewewant = 0;
     } else {
+	/* Scroll the edit window up a page. */
+	edit_scroll(UP, editwinrows - 2);
+
 #ifndef NANO_SMALL
 	/* If we're in smooth scrolling mode and there's at least one
 	 * page of text left, move the current line of the edit window
-	 * up a page, and then get the equivalent x-coordinate of the
-	 * current line. */
+	 * up a page. */
 	if (ISSET(SMOOTH_SCROLL) && openfile->current->lineno >
 		editwinrows - 2) {
 	    int i = 0;
+
 	    for (; i < editwinrows - 2; i++)
 		openfile->current = openfile->current->prev;
-
-	    openfile->current_x = actual_x(openfile->current->data,
-		openfile->placewewant);
 	}
 	/* If we're not in smooth scrolling mode or there isn't at least
 	 * one page of text left, put the cursor at the beginning of the
@@ -131,21 +133,27 @@ void do_page_up(void)
 	else {
 #endif
 	    openfile->current = openfile->edittop;
-	    openfile->current_x = 0;
 	    openfile->placewewant = 0;
 #ifndef NANO_SMALL
 	}
 #endif
-
-	/* Scroll the edit window down a page. */
-	edit_scroll(UP, editwinrows - 2);
     }
 
+    /* Get the equivalent x-coordinate of the current line. */
+    openfile->current_x = actual_x(openfile->current->data,
+	openfile->placewewant);
+
+    /* Update the screen. */
+    edit_redraw(current_save, pww_save);
+
     check_statusblank();
 }
 
 void do_page_down(void)
 {
+    const filestruct *current_save = openfile->current;
+    size_t pww_save = openfile->placewewant;
+
 #ifndef DISABLE_WRAPPING
     wrap_reset();
 #endif
@@ -155,23 +163,21 @@ void do_page_down(void)
     if (openfile->edittop->lineno + editwinrows >
 	openfile->filebot->lineno) {
 	openfile->current = openfile->filebot;
-	openfile->current_x = 0;
 	openfile->placewewant = 0;
     } else {
+	/* Scroll the edit window down a page. */
+	edit_scroll(DOWN, editwinrows - 2);
+
 #ifndef NANO_SMALL
 	/* If we're in smooth scrolling mode and there's at least one
 	 * page of text left, move the current line of the edit window
-	 * down a page, and then get the equivalent x-coordinate of the
-	 * current line. */
+	 * down a page. */
 	if (ISSET(SMOOTH_SCROLL) && openfile->current->lineno +
 		editwinrows - 2 <= openfile->filebot->lineno) {
 	    int i = 0;
 
 	    for (; i < editwinrows - 2; i++)
 		openfile->current = openfile->current->next;
-
-	    openfile->current_x = actual_x(openfile->current->data,
-		openfile->placewewant);
 	}
 	/* If we're not in smooth scrolling mode or there isn't at least
 	 * one page of text left, put the cursor at the beginning of the
@@ -179,16 +185,19 @@ void do_page_down(void)
 	else {
 #endif
 	    openfile->current = openfile->edittop;
-	    openfile->current_x = 0;
 	    openfile->placewewant = 0;
 #ifndef NANO_SMALL
 	}
 #endif
-
-	/* Scroll the edit window down a page. */
-	edit_scroll(DOWN, editwinrows - 2);
     }
 
+    /* Get the equivalent x-coordinate of the current line. */
+    openfile->current_x = actual_x(openfile->current->data,
+	openfile->placewewant);
+
+    /* Update the screen. */
+    edit_redraw(current_save, pww_save);
+
     check_statusblank();
 }
 
@@ -220,15 +229,14 @@ void do_up(void)
 		ISSET(SMOOTH_SCROLL) ? 1 :
 #endif
 		editwinrows / 2);
-    /* Otherwise, update the line we were on before and the line we're
-     * on now.  The former needs to be redrawn if we're not on the first
-     * page, and the latter needs to be redrawn unconditionally. */
-    else {
+
+    /* Update the line we were on before and the line we're on now.  The
+     * former needs to be redrawn if we're not on the first page, and
+     * the latter needs to be drawn unconditionally. */
     if (need_vertical_update(0))
 	update_line(openfile->current->next, 0);
     update_line(openfile->current, openfile->current_x);
 }
-}
 
 void do_down(void)
 {
@@ -258,15 +266,14 @@ void do_down(void)
 		ISSET(SMOOTH_SCROLL) ? 1 :
 #endif
 		editwinrows / 2);
-    /* Otherwise, update the line we were on before and the line we're
-     * on now.  The former needs to be redrawn if we're not on the first
-     * page, and the latter needs to be redrawn unconditionally. */
-    else {
+
+    /* Update the line we were on before and the line we're on now.  The
+     * former needs to be redrawn if we're not on the first page, and
+     * the latter needs to be drawn unconditionally. */
     if (need_vertical_update(0))
 	update_line(openfile->current->prev, 0);
     update_line(openfile->current, openfile->current_x);
 }
-}
 
 void do_left(bool allow_update)
 {

src/winio.c

@@ -3503,8 +3503,11 @@ int need_vertical_update(size_t old_pww)
 /* Scroll the edit window in the given direction and the given number
  * of lines, and draw new lines on the blank lines left after the
  * scrolling.  direction is the direction to scroll, either UP or DOWN,
- * and nlines is the number of lines to scroll.  We assume that current
- * and current_x are up to date, and only change edittop. */
+ * and nlines is the number of lines to scroll.
+ *
+ * Note that we don't draw the topmost or bottommost lines before or
+ * after scrolling, since we can make no assumptions about which of the
+ * two is the current line. */
 void edit_scroll(updown direction, int nlines)
 {
     filestruct *foo;
@@ -3543,19 +3546,15 @@ void edit_scroll(updown direction, int nlines)
     foo = openfile->edittop;
 
     if (direction == DOWN) {
-	for (i = editwinrows - nlines - 1; i > 0 && foo != NULL; i--)
+	for (i = editwinrows - scroll_rows; i > 0 && foo != NULL; i--)
 	    foo = foo->next;
     }
 
     /* Draw new lines on the blank top or bottom lines of the edit
      * window, depending on the value of direction. */
-    scroll_rows++;
-
-    while (scroll_rows > 0 && foo != NULL) {
-	update_line(foo, (foo == openfile->current) ?
-		openfile->current_x : 0);
+    for (; scroll_rows > 0 && foo != NULL; scroll_rows--) {
+	update_line(foo, 0);
 	foo = foo->next;
-	scroll_rows--;
     }
 }