No need to include empty default signal handlers
[projects/chimara/chimara.git] / libchimara / pager.c
index a8904cf2a9cf2bb4bcc808ce1e25779301cf9596..c36edc79cdde8a9ad02501a1c029dc036fd06783 100644 (file)
@@ -2,11 +2,15 @@
 
 #include "pager.h"
 
+/* Not sure if necessary, but this is the margin within which the pager will
+stop paging if it's close to the end of the text buffer */
+#define PAGER_FUZZINESS 1.0
+
 /* Helper function: move the pager to the last visible position in the buffer,
  and return the distance between the pager and the end of the buffer in buffer
  coordinates */
 static void
-move_pager_and_get_scroll_distance(GtkTextView *textview, gint *view_height, gint *scroll_distance)
+move_pager_and_get_scroll_distance(GtkTextView *textview, gint *view_height, gint *scroll_distance, gboolean move )
 {
        GdkRectangle pagerpos, endpos, visiblerect;
        GtkTextIter oldpager, newpager, end;
@@ -23,7 +27,8 @@ move_pager_and_get_scroll_distance(GtkTextView *textview, gint *view_height, gin
        );
        gtk_text_buffer_get_iter_at_mark(buffer, &oldpager, pager);
        
-       gtk_text_buffer_move_mark(buffer, pager, &newpager);
+       if(move)
+               gtk_text_buffer_move_mark(buffer, pager, &newpager);
 
        /* Get the buffer coordinates of the pager and the end iter */
        gtk_text_buffer_get_end_iter(buffer, &end);
@@ -31,9 +36,6 @@ move_pager_and_get_scroll_distance(GtkTextView *textview, gint *view_height, gin
        gtk_text_view_get_iter_location(textview, &newpager, &pagerpos);
        gtk_text_view_get_iter_location(textview, &end, &endpos);
 
-       g_printerr("View height = %d\n", visiblerect.height);
-       g_printerr("End - Pager = %d\n", endpos.y - pagerpos.y);
-       
        *view_height = visiblerect.height;
        *scroll_distance = endpos.y - pagerpos.y;
 }
@@ -43,7 +45,7 @@ static void
 start_paging(winid_t win)
 {
        win->currently_paging = TRUE;
-       g_signal_handler_unblock(win->widget, win->pager_expose_handler);
+       gtk_widget_show(win->pager);
        g_signal_handler_unblock(win->widget, win->pager_keypress_handler);
 }
 
@@ -52,51 +54,33 @@ static void
 stop_paging(winid_t win)
 {
        win->currently_paging = FALSE;
-       g_signal_handler_block(win->widget, win->pager_expose_handler);
+       gtk_widget_hide(win->pager);
        g_signal_handler_block(win->widget, win->pager_keypress_handler);
 }
 
-/* Check whether paging should be done. This function is called inside the 
- * idle handler, after the textview has finished updating. */
-gboolean
-pager_check(gpointer data)
+/* Helper function: If the adjustment is at its maximum value, stop paging */
+static void
+check_paging(GtkAdjustment *adj, winid_t win)
 {
+       double page_size, upper, value;
+       g_object_get(adj,
+               "page-size", &page_size,
+               "upper", &upper,
+               "value", &value,
+               NULL);
+       if(value + PAGER_FUZZINESS >= upper - page_size && win->currently_paging)
+               stop_paging(win);
+}
 
-       printf("pager check...\n");
-       winid_t win = (winid_t) data;
-
-
-       /* Move the pager to the last visible character in the buffer */
-       gint view_height, scroll_distance;
-       move_pager_and_get_scroll_distance( GTK_TEXT_VIEW(win->widget), &view_height, &scroll_distance );
-
-       if(view_height <= 1)
-               /* Paging is unusable when window is too small */
-               return FALSE;
-       
-       if(!win->currently_paging) {
-               if(scroll_distance > view_height) {
-                       start_paging(win);
-                       /* Seriously... */
-                       /* COMPAT: */
-#if GTK_CHECK_VERSION(2,14,0)
-                       gdk_window_invalidate_rect(gtk_widget_get_window(win->widget), NULL, TRUE);
-#else
-                       gdk_window_invalidate_rect(win->widget->window, NULL, TRUE);
-#endif
-               }
-               else if(scroll_distance > 0) {
-                       GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(win->widget));
-                       GtkTextMark *end = gtk_text_buffer_get_mark(buffer, "end_position");
-
-                       gdk_threads_enter();
-                       gtk_text_view_scroll_mark_onscreen(GTK_TEXT_VIEW(win->widget), end);
-                       gdk_threads_leave();
-               }
-       }
-
-       /* Returning FALSE to prevent this function from being called multiple times */
-       return FALSE;
+void
+pager_on_clicked(GtkButton *pager, winid_t win)
+{
+       GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment( GTK_SCROLLED_WINDOW(win->scrolledwindow) );
+       double upper = gtk_adjustment_get_upper(adj);
+       gtk_adjustment_set_value(adj, upper);
+       check_paging(adj, win);
+       /* Give the focus back to the text view */
+       gtk_widget_grab_focus(win->widget);
 }
 
 /* When the user scrolls up in a textbuffer, start paging. */
@@ -105,40 +89,49 @@ pager_after_adjustment_changed(GtkAdjustment *adj, winid_t win)
 {
        /* Move the pager, etc. */
        gint scroll_distance, view_height;
-       move_pager_and_get_scroll_distance( GTK_TEXT_VIEW(win->widget), &view_height, &scroll_distance );
-       
+       move_pager_and_get_scroll_distance( GTK_TEXT_VIEW(win->widget), &view_height, &scroll_distance, TRUE );
+
        if(scroll_distance > 0 && !win->currently_paging)
+       {
                start_paging(win);
+               return;
+       }
        else if(scroll_distance == 0 && win->currently_paging)
+       {
                stop_paging(win);
-       
-       /* Refresh the widget so that any extra "more" prompts disappear */
-       gtk_widget_queue_draw(win->widget);
+               return;
+       }
+
+       check_paging(adj, win);
 }
 
 /* Handle key press events in the textview while paging is active */
 gboolean
 pager_on_key_press_event(GtkTextView *textview, GdkEventKey *event, winid_t win)
 {
-       GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment( GTK_SCROLLED_WINDOW(win->frame) );
-       gdouble step_increment, page_size, upper, lower, value;
+       GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment( GTK_SCROLLED_WINDOW(win->scrolledwindow) );
+       gdouble page_size, upper, lower, value;
        g_object_get(adj, 
                "page-size", &page_size,
-               "step-increment", &step_increment,
                "upper", &upper,
                "lower", &lower,
                "value", &value,
                NULL);
        
        switch (event->keyval) {
-               case GDK_space: case GDK_KP_Space: case GDK_Page_Down: case GDK_KP_Page_Down:
+               case GDK_KEY_space: case GDK_KEY_KP_Space:
+               case GDK_KEY_Page_Down: case GDK_KEY_KP_Page_Down:
+               case GDK_KEY_Return: case GDK_KEY_KP_Enter:
                        gtk_adjustment_set_value(adj, CLAMP(value + page_size, lower, upper - page_size));
+                       check_paging(adj, win);
                        return TRUE;
-               case GDK_Page_Up: case GDK_KP_Page_Up:
+               case GDK_KEY_Page_Up: case GDK_KEY_KP_Page_Up:
                        gtk_adjustment_set_value(adj, CLAMP(value - page_size, lower, upper - page_size));
+                       check_paging(adj, win);
                        return TRUE;
-               case GDK_Return: case GDK_KP_Enter:
-                       gtk_adjustment_set_value(adj, CLAMP(value + step_increment, lower, upper - page_size));
+               case GDK_KEY_End: case GDK_KEY_KP_End:
+                       gtk_adjustment_set_value(adj, upper - page_size);
+                       check_paging(adj, win);
                        return TRUE;
                        /* don't handle "up" and "down", they're used for input history */
        }
@@ -146,25 +139,53 @@ pager_on_key_press_event(GtkTextView *textview, GdkEventKey *event, winid_t win)
        return FALSE; /* if the key wasn't handled here, pass it to other handlers */
 }
 
-/* Draw the "more" prompt on top of the buffer, after the regular expose event has run */
-gboolean
-pager_on_expose(GtkTextView *textview, GdkEventExpose *event, winid_t win)
+/* Check whether paging should be done. This function is called after the
+ * textview has finished validating text positions. */
+void 
+pager_after_size_allocate(GtkTextView *textview, GdkRectangle *allocation, winid_t win)
 {
-       /* Calculate the position of the 'more' tag */
-       gint promptwidth, promptheight;
-       pango_layout_get_pixel_size(win->pager_layout, &promptwidth, &promptheight);
-
-       gint winx, winy, winwidth, winheight;
-       gdk_window_get_position(event->window, &winx, &winy);
-       gdk_drawable_get_size(GDK_DRAWABLE(event->window), &winwidth, &winheight);
-
-       /* Draw the 'more' tag */
-       GdkGC *context = gdk_gc_new(GDK_DRAWABLE(event->window));
-       gdk_draw_layout(event->window, context, 
-               winx + winwidth - promptwidth, 
-               winy + winheight - promptheight, 
-               win->pager_layout);
-
-       return FALSE; /* Propagate event further */
+       /* Move the pager to the last visible character in the buffer */
+       gint view_height, scroll_distance; 
+       move_pager_and_get_scroll_distance(GTK_TEXT_VIEW(win->widget), &view_height, &scroll_distance, FALSE);
+
+       if(view_height <= 1)
+               /* Paging is unusable when window is too small */
+               return;
+
+       /* If not in interactive mode, then just scroll to the bottom. */
+       ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(GTK_WIDGET(textview), CHIMARA_TYPE_GLK));
+       g_assert(glk);
+       if(!chimara_glk_get_interactive(glk)) {
+               GtkTextIter end;
+               gtk_text_buffer_get_end_iter(gtk_text_view_get_buffer(textview), &end);
+               gtk_text_view_scroll_to_iter(textview, &end, 0.0, TRUE, 0.0, 0.0);
+               return;
+       }
+       
+       /* Scroll past text already read by user. This is automatic scrolling, so disable the pager_ajustment_handler
+        * first, that acts on the belief the scolling is performed by the user. */
+       GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(win->scrolledwindow));
+       g_signal_handler_block(adj, win->pager_adjustment_handler);
+       GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(win->widget));
+       GtkTextMark *pager_position = gtk_text_buffer_get_mark(buffer, "pager_position");
+       gtk_text_view_scroll_to_mark(GTK_TEXT_VIEW(win->widget), pager_position, 0.0, TRUE, 0.0, 0.0);
+       g_signal_handler_unblock(adj, win->pager_adjustment_handler);
+       
+       if(!win->currently_paging) {
+               if(scroll_distance > view_height) {
+                       start_paging(win);
+                       gdk_window_invalidate_rect(gtk_widget_get_window(win->widget), NULL, TRUE);
+               }
+       }
 }
 
+void
+pager_update(winid_t win)
+{
+       GtkTextIter input_iter;
+       GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(win->widget));
+       GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
+       GtkTextMark *pager_position = gtk_text_buffer_get_mark(buffer, "pager_position");
+       gtk_text_buffer_get_iter_at_mark(buffer, &input_iter, input_position);
+       gtk_text_buffer_move_mark(buffer, pager_position, &input_iter);
+}