Repeat page scrolling when holding the button

When the page scroll mode is enabled, pressing and holding the scrollbar
will keep scrolling pages on that direction until the mouse button is
released.

1 files changed, 29 insertions, 5 deletions

diff --git a/dw/fltkviewport.cc b/dw/fltkviewport.cc
index e9169495..fc9a0bed 100644
--- a/dw/fltkviewport.cc
+++ b/dw/fltkviewport.cc
@@ -74,6 +74,10 @@ FltkViewport::FltkViewport (int X, int Y, int W, int H, const char *label):
    horScrolling = verScrolling = dragScrolling = 0;
    scrollbarPageMode = false;
    pageOverlap = 50;
+   pageScrolling = core::NONE_CMD;
+
+   pageScrollDelay = 0.300;
+   pageScrollInterval = 0.100;
 
    gadgetOrientation[0] = GADGET_HORIZONTAL;
    gadgetOrientation[1] = GADGET_HORIZONTAL;
@@ -296,11 +300,19 @@ int FltkViewport::handle (int event)
    case FL_PUSH:
       if (vscrollbar->visible() && Fl::event_inside(vscrollbar)) {
          if (scrollbarPageMode ^ (bool) Fl::event_shift()) {
-            if (Fl::event_button() == FL_LEFT_MOUSE) {
-               scroll(core::SCREEN_DOWN_CMD);
-               return 1;
-            } else if (Fl::event_button() == FL_RIGHT_MOUSE) {
-               scroll(core::SCREEN_UP_CMD);
+            if (Fl::event_button() == FL_LEFT_MOUSE)
+               pageScrolling = core::SCREEN_DOWN_CMD;
+            else if (Fl::event_button() == FL_RIGHT_MOUSE)
+               pageScrolling = core::SCREEN_UP_CMD;
+            else
+               pageScrolling = core::NONE_CMD;
+
+            if (pageScrolling != core::NONE_CMD) {
+               scroll(pageScrolling);
+               /* Repeat until released */
+               if (!Fl::has_timeout(repeatPageScroll, this))
+                  Fl::add_timeout(pageScrollDelay, repeatPageScroll, this);
+
                return 1;
             }
          }
@@ -363,6 +375,7 @@ int FltkViewport::handle (int event)
       break;
 
    case FL_RELEASE:
+      Fl::remove_timeout(repeatPageScroll);
       Fl::remove_timeout(selectionScroll);
       if (Fl::event_button() == FL_MIDDLE_MOUSE) {
          setCursor (core::style::CURSOR_DEFAULT);
@@ -547,6 +560,17 @@ void FltkViewport::selectionScroll (void *data)
    Fl::repeat_timeout(0.025, selectionScroll, data);
 }
 
+void FltkViewport::repeatPageScroll ()
+{
+   scroll(pageScrolling);
+   Fl::repeat_timeout(pageScrollInterval, repeatPageScroll, this);
+}
+
+void FltkViewport::repeatPageScroll (void *data)
+{
+   ((FltkViewport *)data)->repeatPageScroll ();
+}
+
 void FltkViewport::setScrollbarOnLeft (bool enable)
 {
    scrollbarOnLeft = enable ? 1 : 0;