[evince] libview: Make the caret cursor movements relative to the selection

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 1141042bd051d0e1ccca349dc0c0c35a2791c775
Author: Antia Puentes <apuentes igalia com>
Date:   Fri Jul 25 11:10:22 2014 +0200

    libview: Make the caret cursor movements relative to the selection
    
     * Right/left arrow: Position the cursor in the start/end
       boundaries of the selection.
     * Up/Down arrow: Position the cursor one line before/after the
       start/end boundary of the selection.
     * <Ctrl>Right/left arrow: Move by word as it the cursor were in
       the start/end boundaries of the selection.
     * Home/End: Move to the beggining/end of the line containing the
       start/end boundary of the selection.
    
    Fixed also the equivalent selection commands (+<Shift>)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=704631

 libview/ev-view.c |  138 ++++++++++++++++++++++++++++++++++++++++-------------
 1 files changed, 105 insertions(+), 33 deletions(-)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 4c346e9..e7c255c 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -4632,11 +4632,9 @@ position_caret_cursor_at_doc_point (EvView *view,
        if (view->cursor_offset != offset || view->cursor_page != page) {
                view->cursor_offset = offset;
                view->cursor_page = page;
-
-               return TRUE;
        }
 
-       return FALSE;
+       return TRUE;
 }
 
 static gboolean
@@ -5625,7 +5623,9 @@ cursor_clear_selection (EvView  *view,
        GList                *l;
        EvViewSelection      *selection;
        cairo_rectangle_int_t rect;
+       cairo_region_t        *region, *tmp_region = NULL;
        gint                  doc_x, doc_y;
+       GdkRectangle          area;
 
        /* When clearing the selection, move the cursor to
         * the limits of the selection region.
@@ -5635,19 +5635,57 @@ cursor_clear_selection (EvView  *view,
 
        l = forward ? g_list_last (view->selection_info.selections) : view->selection_info.selections;
        selection = (EvViewSelection *)l->data;
-       if (!selection->covered_region || cairo_region_is_empty (selection->covered_region))
-               return FALSE;
 
-       cairo_region_get_rectangle (selection->covered_region,
-                                   forward ? cairo_region_num_rectangles (selection->covered_region) - 1 : 0,
+       region = selection->covered_region;
+
+       /* When the selection boundary is not in the current page,
+          get the cairo region */
+       if (!region || cairo_region_is_empty (region)) {
+               EvRenderContext *rc;
+               EvPage          *page;
+
+               ev_document_doc_mutex_lock ();
+
+               page = ev_document_get_page (view->document, selection->page);
+               rc = ev_render_context_new (page, view->rotation, view->scale);
+               g_object_unref (page);
+
+               tmp_region = ev_selection_get_selection_region (EV_SELECTION (view->document),
+                                                               rc,
+                                                               EV_SELECTION_STYLE_GLYPH,
+                                                               &(selection->rect));
+               g_object_unref (rc);
+
+               ev_document_doc_mutex_unlock();
+
+               if (!tmp_region || cairo_region_is_empty (tmp_region)) {
+                       cairo_region_destroy (tmp_region);
+                       return FALSE;
+               }
+
+               region = tmp_region;
+       }
+
+       cairo_region_get_rectangle (region,
+                                   forward ? cairo_region_num_rectangles (region) - 1 : 0,
                                    &rect);
 
+       if (tmp_region) {
+               cairo_region_destroy (tmp_region);
+               region = NULL;
+       }
+
        if (!get_doc_point_from_offset (view, selection->page,
                                        forward ? rect.x + rect.width : rect.x,
                                        rect.y + (rect.height / 2), &doc_x, &doc_y))
                return FALSE;
 
-       position_caret_cursor_at_doc_point (view, selection->page, doc_x, doc_y);
+       if (!position_caret_cursor_at_doc_point (view, selection->page, doc_x, doc_y))
+               return FALSE;
+
+       if (get_caret_cursor_area (view, view->cursor_page, view->cursor_offset, &area))
+               view->cursor_line_offset = area.x;
+
        return TRUE;
 }
 
@@ -5661,6 +5699,9 @@ ev_view_move_cursor (EvView         *view,
        GdkRectangle    prev_rect;
        gint            prev_offset;
        gint            prev_page;
+       GdkRectangle    select_start_rect;
+       gint            select_start_offset;
+       gint            select_start_page;
        cairo_region_t *damage_region;
        gboolean        clear_selections = FALSE;
 
@@ -5673,11 +5714,20 @@ ev_view_move_cursor (EvView         *view,
        prev_offset = view->cursor_offset;
        prev_page = view->cursor_page;
 
+       if (extend_selections) {
+               select_start_offset = view->cursor_offset;
+               select_start_page = view->cursor_page;
+       }
+
        clear_selections = !extend_selections && view->selection_info.selections != NULL;
 
        switch (step) {
        case GTK_MOVEMENT_VISUAL_POSITIONS:
-               if (!clear_selections || !cursor_clear_selection (view, count > 0)) {
+               /* If we have a selection, we want the cursor to be moved to the limits
+                  of the selection. */
+               if (clear_selections) {
+                       cursor_clear_selection (view, count > 0);
+               } else {
                        while (count > 0) {
                                cursor_forward_char (view);
                                count--;
@@ -5689,36 +5739,55 @@ ev_view_move_cursor (EvView         *view,
                }
                break;
        case GTK_MOVEMENT_WORDS:
-               while (count > 0) {
-                       cursor_forward_word_end (view);
-                       count--;
-               }
-               while (count < 0) {
-                       cursor_backward_word_start (view);
-                       count++;
+               /* For this and the next movements, if we have a selection we want the movement
+                  to be relative to the selection limits. We only do the movement if the selection
+                  was sucessfully cleared */
+               if (!clear_selections || cursor_clear_selection (view, count > 0)) {
+                       while (count > 0) {
+                               cursor_forward_word_end (view);
+                               count--;
+                       }
+                       while (count < 0) {
+                               cursor_backward_word_start (view);
+                               count++;
+                       }
                }
                break;
        case GTK_MOVEMENT_DISPLAY_LINES:
-               while (count > 0) {
-                       cursor_forward_line (view);
-                       count--;
-               }
-               while (count < 0) {
-                       cursor_backward_line (view);
-                       count++;
+               if (!clear_selections || cursor_clear_selection (view, count > 0)) {
+                       while(count > 0) {
+                               cursor_forward_line (view);
+                               count--;
+                       }
+                       while (count < 0) {
+                               cursor_backward_line (view);
+                               count++;
+                       }
                }
                break;
        case GTK_MOVEMENT_DISPLAY_LINE_ENDS:
-               if (count > 0)
-                       cursor_go_to_line_end (view);
-               else if (count < 0)
-                       cursor_go_to_line_start (view);
+               if (!clear_selections  || cursor_clear_selection (view, count > 0)) {
+                       if (count > 0)
+                               cursor_go_to_line_end (view);
+                       else if (count < 0)
+                               cursor_go_to_line_start (view);
+               }
                break;
        case GTK_MOVEMENT_BUFFER_ENDS:
-               if (count > 0)
-                       cursor_go_to_document_end (view);
-               else if (count < 0)
-                       cursor_go_to_document_start (view);
+               /* If there is a previous selection, move the cursor to the beginning of the
+                  selection (it will be used as the new selection starting point, when
+                  selecting from the current point to the beginning or to the end of the doc */
+               if (!clear_selections || cursor_clear_selection (view, FALSE)) {
+                       if (extend_selections && (select_start_offset != view->cursor_offset ||
+                                                 select_start_page != view->cursor_page)) {
+                               select_start_offset = view->cursor_offset;
+                               select_start_page = view->cursor_page;
+                       }
+                       if (count > 0)
+                               cursor_go_to_document_end (view);
+                       else if (count < 0)
+                               cursor_go_to_document_start (view);
+               }
                break;
        default:
                g_assert_not_reached ();
@@ -5773,8 +5842,11 @@ ev_view_move_cursor (EvView         *view,
        if (extend_selections && EV_IS_SELECTION (view->document)) {
                GdkPoint start_point, end_point;
 
-               start_point.x = prev_rect.x + view->scroll_x;
-               start_point.y = prev_rect.y + (prev_rect.height / 2) + view->scroll_y;
+               if (!get_caret_cursor_area (view, select_start_page, select_start_offset, &select_start_rect))
+                       return TRUE;
+
+               start_point.x = select_start_rect.x + view->scroll_x;
+               start_point.y = select_start_rect.y + (select_start_rect.height / 2) + view->scroll_y;
 
                end_point.x = rect.x;
                end_point.y = rect.y + rect.height / 2;