properly overhaul edit_scroll() to update the screen on its own this

time, convert the vertical movement functions to use the new version of
it, and simplify them where possible

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2876 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

diff --git a/ChangeLog b/ChangeLog
index d7e591b7777417c1bd50bcf5c427cbd539792779..87264452275032dfa06bad4a21868f2526a8dd2e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -34,6 +34,16 @@ CVS code -
          (DLR)
        - Consistently make the flags global and any variables used to
          hold it longs. (DLR)
+       - Make edit_scroll() sophisticated enough to keep track of
+         current and current_x and update the lines before and after
+         the scrolled region, and change the movement functions that
+         use edit_scroll() to (a) set current and current_x before
+         calling it, and (b) no longer call edit_redraw() afterward,
+         since it's now unnecessary.  These changes eliminate
+         redundant screen updates when the mark is on, since the mark
+         display depends on current and current_x.  Changes to
+         edit_scroll(), do_page_up(), do_page_down(), do_up(), and
+         do_down(). (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
@@ -59,6 +69,12 @@ CVS code -
 - global.c:
   shortcut_init()
        - Simplify wording of nano_gotoline_msg. (Jordi and Ken Tyler)
+- move.c:
+  do_first_line(), do_last_line()
+       - Simplify by only using edit_redraw(). (DLR)
+  do_page_up(), do_page_down()
+       - If there's less than a page of text onscreen, just call
+         do_(first|last)_line(). (DLR)
 - nano.c:
   usage()
        - Properly mention the support for "[+LINE,COLUMN]" on the
@@ -118,7 +134,7 @@ CVS code -
          as the alternate spell checking code is now the only place
          where it's used. (DLR)
 - winio.c:
-  edit_scroll(), edit_redraw(), edit_refresh()
+  edit_redraw(), edit_refresh()
        - Clean up and simplify. (DLR)
   edit_update()
        - Since we no longer use TOP, remove references to it.  Also,

diff --git a/src/move.c b/src/move.c
index d12bbb599b289a93a15b276ceea18a431b8e6a1e..541b7df619ccfeb30faec5dc37f2058db319a044 100644 (file)
--- a/src/move.c
+++ b/src/move.c
@@ -32,28 +32,27 @@
 
 void do_first_line(void)
 {
+    const filestruct *current_save = openfile->current;
     size_t pww_save = openfile->placewewant;
 
     openfile->current = openfile->fileage;
     openfile->current_x = 0;
     openfile->placewewant = 0;
 
-    if (openfile->edittop != openfile->fileage ||
-       need_vertical_update(pww_save))
-       edit_update(CENTER);
+    edit_redraw(current_save, pww_save);
 }
 
 void do_last_line(void)
 {
+    const filestruct *current_save = openfile->current;
     size_t pww_save = openfile->placewewant;
 
     openfile->current = openfile->filebot;
     openfile->current_x = 0;
     openfile->placewewant = 0;
+    openfile->current_y = editwinrows - 1;
 
-    if (openfile->edittop->lineno + (editwinrows / 2) !=
-       openfile->filebot->lineno || need_vertical_update(pww_save))
-       edit_update(CENTER);
+    edit_redraw(current_save, pww_save);
 }
 
 void do_home(void)
@@ -100,103 +99,81 @@ 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
 
-    /* If the first line of the file is onscreen, move current up there
-     * and put the cursor at the beginning of the line. */
-    if (openfile->edittop == openfile->fileage) {
-       openfile->current = openfile->fileage;
-       openfile->placewewant = 0;
-    } else {
-       /* Scroll the edit window up a page. */
-       edit_scroll(UP, editwinrows - 2);
-
+    /* If there's less than a page of text left on the screen, put the
+     * cursor at the beginning of the first line of the file, and then
+     * update the edit window. */
+    if (openfile->current->lineno <= editwinrows - 2)
+       do_first_line();
+    else {
+       int i;
+
+       /* If we're not in smooth scrolling mode, put the cursor at the
+        * beginning of the top line of the edit window, as Pico
+        * does. */
 #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. */
-       if (ISSET(SMOOTH_SCROLL) && openfile->current->lineno >
-               editwinrows - 2) {
-           int i = 0;
-
-           for (; i < editwinrows - 2; i++)
-               openfile->current = openfile->current->prev;
-       }
-       /* 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
-        * top line of the edit window, as Pico does. */
-       else {
+       if (!ISSET(SMOOTH_SCROLL)) {
 #endif
            openfile->current = openfile->edittop;
            openfile->placewewant = 0;
 #ifndef NANO_SMALL
        }
 #endif
-    }
 
-    /* Get the equivalent x-coordinate of the current line. */
-    openfile->current_x = actual_x(openfile->current->data,
-       openfile->placewewant);
+       for (i = editwinrows - 2; i > 0 && openfile->current->prev !=
+               NULL; i--)
+           openfile->current = openfile->current->prev;
 
-    /* Update the screen. */
-    edit_redraw(current_save, pww_save);
+       openfile->current_x = actual_x(openfile->current->data,
+           openfile->placewewant);
+
+       /* Scroll the edit window up a page. */
+       edit_scroll(UP, editwinrows - 2);
+    }
 
     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
 
-    /* If the last line of the file is onscreen, move current down
-     * there and put the cursor at the beginning of the line. */
-    if (openfile->edittop->lineno + editwinrows >
-       openfile->filebot->lineno) {
-       openfile->current = openfile->filebot;
-       openfile->placewewant = 0;
-    } else {
-       /* Scroll the edit window down a page. */
-       edit_scroll(DOWN, editwinrows - 2);
+    /* If there's less than a page of text left on the screen, put the
+     * cursor at the beginning of the last line of the file, and then
+     * update the edit window. */
+    if (openfile->current->lineno + editwinrows - 2 >=
+       openfile->filebot->lineno)
+       do_last_line();
+    else {
+       /* If we're not in smooth scrolling mode, put the cursor at the
+        * beginning of the top line of the edit window, as Pico
+        * does. */
+       int i;
 
 #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. */
-       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;
-       }
-       /* 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
-        * top line of the edit window, as Pico does. */
-       else {
+       if (!ISSET(SMOOTH_SCROLL)) {
 #endif
            openfile->current = openfile->edittop;
            openfile->placewewant = 0;
 #ifndef NANO_SMALL
        }
 #endif
-    }
 
-    /* Get the equivalent x-coordinate of the current line. */
-    openfile->current_x = actual_x(openfile->current->data,
-       openfile->placewewant);
+       for (i = editwinrows - 2; i > 0 && openfile->current->next !=
+               NULL; i--)
+           openfile->current = openfile->current->next;
 
-    /* Update the screen. */
-    edit_redraw(current_save, pww_save);
+       openfile->current_x = actual_x(openfile->current->data,
+               openfile->placewewant);
+
+       /* Scroll the edit window down a page. */
+       edit_scroll(DOWN, editwinrows - 2);
+    }
 
     check_statusblank();
 }
@@ -228,13 +205,14 @@ void do_up(void)
                ISSET(SMOOTH_SCROLL) ? 1 :
 #endif
                editwinrows / 2);
-
     /* 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);
+    else {
+       if (need_vertical_update(0))
+           update_line(openfile->current->next, 0);
+       update_line(openfile->current, openfile->current_x);
+    }
 }
 
 void do_down(void)
@@ -264,13 +242,14 @@ void do_down(void)
                ISSET(SMOOTH_SCROLL) ? 1 :
 #endif
                editwinrows / 2);
-
     /* 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);
+    else {
+       if (need_vertical_update(0))
+           update_line(openfile->current->prev, 0);
+       update_line(openfile->current, openfile->current_x);
+    }
 }
 
 void do_left(bool allow_update)

diff --git a/src/winio.c b/src/winio.c
index dffbeab93dfe7706e4baf028fa0a0d8ed2a1a8bc..e1dd6b5259d069168a1c7a3964086ca975c091c0 100644 (file)
--- a/src/winio.c
+++ b/src/winio.c
@@ -3503,17 +3503,12 @@ 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 the topmost and bottommost lines of the scrolled
- * region are where the current line was before and will be after
- * scrolling, and hence don't draw them, since we can't know which is
- * which.  edit_redraw() should be used to draw these lines, and to
- * redraw marked lines, if applicable. */
+ * and nlines is the number of lines to scroll.  We change edittop, and
+ * assume that current and current_x are up to date. */
 void edit_scroll(updown direction, int nlines)
 {
     const filestruct *foo;
-    int i, scroll_rows = 0;
+    int i;
 
     /* Scrolling less than one line or more than editwinrows lines is
      * redundant, so don't allow it. */
@@ -3521,10 +3516,8 @@ void edit_scroll(updown direction, int nlines)
        return;
 
     /* Move the top line of the edit window up or down (depending on the
-     * value of direction) nlines lines.  If there are fewer lines of
-     * text than that left, move it to the top or bottom line of the
-     * file (depending on the value of direction).  Keep track of
-     * how many lines we moved in scroll_rows. */
+     * value of direction) nlines lines, or as many lines as we can if
+     * there are fewer than nlines lines available. */
     for (i = nlines; i > 0; i--) {
        if (direction == UP) {
            if (openfile->edittop->prev == NULL)
@@ -3535,28 +3528,34 @@ void edit_scroll(updown direction, int nlines)
                break;
            openfile->edittop = openfile->edittop->next;
        }
-
-       scroll_rows++;
     }
 
-    /* Scroll the text on the screen up or down scroll_rows lines,
-     * depending on the value of direction. */
+    /* Scroll the text on the screen up or down nlines lines, depending
+     * on the value of direction. */
     scrollok(edit, TRUE);
-    wscrl(edit, (direction == UP) ? -scroll_rows : scroll_rows);
+    wscrl(edit, (direction == UP) ? -nlines : nlines);
     scrollok(edit, FALSE);
 
+    /* Add two to nlines, to account for the lines before and after the
+     * scrolled region. */
+    nlines += 2;
+
+    /* If we scrolled up, we're on the line before the scrolled
+     * region. */
     foo = openfile->edittop;
 
+    /* If we scrolled down, move down to the line before the scrolled
+     * region. */
     if (direction == DOWN) {
-       for (i = editwinrows - scroll_rows; i > 0 && foo != NULL; i--)
+       for (i = editwinrows - nlines; 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, and skipping the
-     * topmost and bottommost lines. */
-    for (; scroll_rows > 0 && foo != NULL; scroll_rows--) {
-       update_line(foo, 0);
+    /* Draw new lines on the blank lines before, inside, and after the
+     * scrolled region. */
+    for (; nlines > 0 && foo != NULL; nlines--) {
+       update_line(foo, (foo == openfile->current) ?
+               openfile->current_x : 0);
        foo = foo->next;
     }
 }