[gtk/wip/otte/listview: 14/40] gridview: Implement anchors and scrolling
- From: Benjamin Otte <otte src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/wip/otte/listview: 14/40] gridview: Implement anchors and scrolling
- Date: Tue, 29 Oct 2019 03:56:30 +0000 (UTC)
commit 151970779011c4aade35d12c8554523715e6fd92
Author: Benjamin Otte <otte redhat com>
Date: Sat Oct 19 18:20:04 2019 +0200
gridview: Implement anchors and scrolling
gtk/gtkgridview.c | 481 ++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 450 insertions(+), 31 deletions(-)
---
diff --git a/gtk/gtkgridview.c b/gtk/gtkgridview.c
index cdad9457ed..27b561c579 100644
--- a/gtk/gtkgridview.c
+++ b/gtk/gtkgridview.c
@@ -69,9 +69,13 @@ struct _GtkGridView
/* set in size_allocate */
guint n_columns;
double column_width;
+ int unknown_row_height;
GtkListItemTracker *anchor;
- double anchor_align;
+ double anchor_xalign;
+ double anchor_yalign;
+ guint anchor_xstart : 1;
+ guint anchor_ystart : 1;
};
struct _Cell
@@ -135,47 +139,463 @@ dump (GtkGridView *self)
g_print (" => %u widgets in %u list rows\n", n_widgets, n_list_rows);
}
+
+/*<private>
+ * gtk_grid_view_get_cell_at_y:
+ * @self: a #GtkGridView
+ * @y: an offset in direction of @self's orientation
+ * @position: (out caller-allocates) (optional): stores the position
+ * index of the returned row
+ * @offset: (out caller-allocates) (optional): stores the offset
+ * in pixels between y and top of cell.
+ * @offset: (out caller-allocates) (optional): stores the height
+ * of the cell
+ *
+ * Gets the Cell that occupies the leftmost position in the row at offset
+ * @y into the primary direction.
+ *
+ * If y is larger than the height of all cells, %NULL will be returned.
+ * In particular that means that for an emtpy grid, %NULL is returned
+ * for any value.
+ *
+ * Returns: (nullable): The first cell at offset y or %NULL if none
+ **/
+static Cell *
+gtk_grid_view_get_cell_at_y (GtkGridView *self,
+ int y,
+ guint *position,
+ int *offset,
+ int *size)
+{
+ Cell *cell, *tmp;
+ guint pos;
+
+ cell = gtk_list_item_manager_get_root (self->item_manager);
+ pos = 0;
+
+ while (cell)
+ {
+ tmp = gtk_rb_tree_node_get_left (cell);
+ if (tmp)
+ {
+ CellAugment *aug = gtk_list_item_manager_get_item_augment (self->item_manager, tmp);
+ if (y < aug->size)
+ {
+ cell = tmp;
+ continue;
+ }
+ y -= aug->size;
+ pos += aug->parent.n_items;
+ }
+
+ if (y < cell->size)
+ break;
+ y -= cell->size;
+ pos += cell->parent.n_items;
+
+ cell = gtk_rb_tree_node_get_right (cell);
+ }
+
+ if (cell == NULL)
+ {
+ if (position)
+ *position = 0;
+ if (offset)
+ *offset = 0;
+ if (size)
+ *size = 0;
+ return NULL;
+ }
+
+ /* We know have the (range of) cell(s) that contains this offset.
+ * Now for the hard part of computing which index this actually is.
+ */
+ if (offset || position || size)
+ {
+ guint n_items = cell->parent.n_items;
+ guint no_widget_rows, skip;
+
+ /* skip remaining items at end of row */
+ if (pos % self->n_columns)
+ {
+ skip = pos - pos % self->n_columns;
+ n_items -= skip;
+ pos += skip;
+ }
+
+ /* Skip all the rows this index doesn't go into */
+ no_widget_rows = (n_items - 1) / self->n_columns;
+ skip = MIN (y / self->unknown_row_height, no_widget_rows);
+ y -= skip * self->unknown_row_height;
+ pos += self->n_columns * skip;
+
+ if (position)
+ *position = pos;
+ if (offset)
+ *offset = y;
+ if (size)
+ {
+ if (skip < no_widget_rows)
+ *size = self->unknown_row_height;
+ else
+ *size = cell->size - no_widget_rows * self->unknown_row_height;
+ }
+ }
+
+ return cell;
+}
+
+/*<private>
+ * gtk_grid_view_get_size_at_position:
+ * @self: a #GtkGridView
+ * @position: position of the item
+ * @offset: (out caller-allocates) (optional): stores the y coordinate
+ * of the cell (x coordinate for horizontal grids)
+ * @size: (out caller-allocates) (optional): stores the height
+ * of the cell (width for horizontal grids)
+ *
+ * Computes where the cell at @position is allocated.
+ *
+ * If position is larger than the number of items, %FALSE will be returned.
+ * In particular that means that for an emtpy grid, %FALSE is returned
+ * for any value.
+ *
+ * Returns: (nullable): %TRUE if the cell existed, %FALSE otherwise
+ **/
+static gboolean
+gtk_grid_view_get_size_at_position (GtkGridView *self,
+ guint position,
+ int *offset,
+ int *size)
+{
+ Cell *cell, *tmp;
+ int y;
+
+ cell = gtk_list_item_manager_get_root (self->item_manager);
+ y = 0;
+ position -= position % self->n_columns;
+
+ while (cell)
+ {
+ tmp = gtk_rb_tree_node_get_left (cell);
+ if (tmp)
+ {
+ CellAugment *aug = gtk_list_item_manager_get_item_augment (self->item_manager, tmp);
+ if (position < aug->parent.n_items)
+ {
+ cell = tmp;
+ continue;
+ }
+ position -= aug->parent.n_items;
+ y += aug->size;
+ }
+
+ if (position < cell->parent.n_items)
+ break;
+ y += cell->size;
+ position -= cell->parent.n_items;
+
+ cell = gtk_rb_tree_node_get_right (cell);
+ }
+
+ if (cell == NULL)
+ {
+ if (offset)
+ *offset = 0;
+ if (size)
+ *size = 0;
+ return FALSE;
+ }
+
+ /* We know have the (range of) cell(s) that contains this offset.
+ * Now for the hard part of computing which index this actually is.
+ */
+ if (offset || size)
+ {
+ guint n_items = cell->parent.n_items;
+ guint skip;
+
+ /* skip remaining items at end of row */
+ if (position % self->n_columns)
+ {
+ skip = position % self->n_columns;
+ n_items -= skip;
+ position -= skip;
+ }
+
+ /* Skip all the rows this index doesn't go into */
+ skip = position / self->n_columns;
+ n_items -= skip * self->n_columns;
+ y += skip * self->unknown_row_height;
+
+ if (offset)
+ *offset = y;
+ if (size)
+ {
+ if (n_items > self->n_columns)
+ *size = self->unknown_row_height;
+ else
+ *size = cell->size - skip * self->unknown_row_height;
+ }
+ }
+
+ return TRUE;
+}
+
static void
gtk_grid_view_set_anchor (GtkGridView *self,
guint position,
- double align)
+ double xalign,
+ gboolean xstart,
+ double yalign,
+ gboolean ystart)
{
gtk_list_item_tracker_set_position (self->item_manager,
self->anchor,
- 0,
- (GTK_GRID_VIEW_MIN_VISIBLE_ROWS * align + 1) * self->max_columns,
- (GTK_GRID_VIEW_MIN_VISIBLE_ROWS * (1 - align) + 1) *
self->max_columns);
- if (self->anchor_align != align)
+ position,
+ (GTK_GRID_VIEW_MIN_VISIBLE_ROWS * yalign + 1) * self->max_columns,
+ (GTK_GRID_VIEW_MIN_VISIBLE_ROWS * (1 - yalign) + 1) *
self->max_columns);
+
+ if (self->anchor_xalign != xalign ||
+ self->anchor_xstart != xstart ||
+ self->anchor_yalign != yalign ||
+ self->anchor_ystart != ystart)
{
- self->anchor_align = align;
+ self->anchor_xalign = xalign;
+ self->anchor_xstart = xstart;
+ self->anchor_yalign = yalign;
+ self->anchor_ystart = ystart;
gtk_widget_queue_allocate (GTK_WIDGET (self));
}
}
+static gboolean
+gtk_grid_view_adjustment_is_flipped (GtkGridView *self,
+ GtkOrientation orientation)
+{
+ if (orientation == GTK_ORIENTATION_VERTICAL)
+ return FALSE;
+
+ return gtk_widget_get_direction (GTK_WIDGET (self)) == GTK_TEXT_DIR_RTL;
+}
+
static void
gtk_grid_view_adjustment_value_changed_cb (GtkAdjustment *adjustment,
GtkGridView *self)
{
+ int page_size, total_size, value, from_start;
+ guint pos, anchor_pos, n_items;
+ int offset, height, top, bottom;
+ double xalign, yalign;
+ gboolean xstart, ystart;
+
+ page_size = gtk_adjustment_get_page_size (adjustment);
+ value = gtk_adjustment_get_value (adjustment);
+ total_size = gtk_adjustment_get_upper (adjustment);
+ anchor_pos = gtk_list_item_tracker_get_position (self->item_manager, self->anchor);
+ n_items = g_list_model_get_n_items (self->model);
+ if (gtk_grid_view_adjustment_is_flipped (self, self->orientation))
+ value = total_size - page_size - value;
+
+ if (adjustment == self->adjustment[self->orientation])
+ {
+ /* Compute how far down we've scrolled. That's the height
+ * we want to align to. */
+ yalign = (double) value / (total_size - page_size);
+ from_start = round (yalign * page_size);
+
+ /* We want the cell that far down the page */
+ if (gtk_grid_view_get_cell_at_y (self,
+ value + from_start,
+ &pos,
+ &offset,
+ &height))
+ {
+ /* offset from value - which is where we wanna scroll to */
+ top = from_start - offset;
+ bottom = top + height;
+
+ /* find an anchor that is in the visible area */
+ if (top > 0 && bottom < page_size)
+ ystart = from_start - top <= bottom - from_start;
+ else if (top > 0)
+ ystart = TRUE;
+ else if (bottom < page_size)
+ ystart = FALSE;
+ else
+ {
+ /* This is the case where the cell occupies the whole visible area.
+ * It's also the only case where align will not end up in [0..1] */
+ ystart = from_start - top <= bottom - from_start;
+ }
+
+ /* Now compute the align so that when anchoring to the looked
+ * up cell, the position is pixel-exact.
+ */
+ yalign = (double) (ystart ? top : bottom) / page_size;
+ }
+ else
+ {
+ /* Happens if we scroll down to the end - we will query
+ * exactly the pixel behind the last one we can get a cell for.
+ * So take the last row. */
+ pos = n_items - 1;
+ pos = pos - pos % self->n_columns;
+ yalign = 1.0;
+ ystart = FALSE;
+ }
+
+ /* And finally, keep the column anchor intact. */
+ anchor_pos %= self->n_columns;
+ pos += anchor_pos;
+ xstart = self->anchor_xstart;
+ xalign = self->anchor_xalign;
+ }
+ else
+ {
+ xalign = (double) value / (total_size - page_size);
+ from_start = round (xalign * page_size);
+ pos = floor ((value + from_start) / self->column_width);
+ if (pos >= self->n_columns)
+ {
+ /* scrolling to the end sets pos to exactly self->n_columns */
+ pos = self->n_columns - 1;
+ xstart = FALSE;
+ xalign = 1.0;
+ }
+ else
+ {
+ top = ceil (self->column_width * pos) - value;
+ bottom = ceil (self->column_width * (pos + 1)) - value;
+
+ /* offset from value - which is where we wanna scroll to */
+
+ /* find an anchor that is in the visible area */
+ if (top > 0 && bottom < page_size)
+ xstart = from_start - top <= bottom - from_start;
+ else if (top > 0)
+ xstart = TRUE;
+ else if (bottom < page_size)
+ xstart = FALSE;
+ else
+ xstart = from_start - top <= bottom - from_start;
+
+ xalign = (double) (xstart ? top : bottom) / page_size;
+ }
+
+ /* And finally, keep the row anchor intact. */
+ pos += (anchor_pos - anchor_pos % self->n_columns);
+ yalign = self->anchor_yalign;
+ ystart = self->anchor_ystart;
+ }
+
+ if (pos >= n_items)
+ {
+ /* Ugh, we're in the last row and don't have enough items
+ * to fill the row.
+ * Do it the hard way then... */
+ adjustment = self->adjustment[OPPOSITE_ORIENTATION (self->orientation)];
+
+ pos = n_items - 1;
+ xstart = FALSE;
+ xalign = (ceil (self->column_width * (pos % self->n_columns + 1))
+ - gtk_adjustment_get_value (adjustment))
+ / gtk_adjustment_get_page_size (adjustment);
+ }
+
+ gtk_grid_view_set_anchor (self, pos, xalign, xstart, yalign, ystart);
+
gtk_widget_queue_allocate (GTK_WIDGET (self));
}
-static void
-gtk_grid_view_update_adjustments (GtkGridView *self,
- GtkOrientation orientation)
+static int
+gtk_grid_view_update_adjustment_with_values (GtkGridView *self,
+ GtkOrientation orientation,
+ int value,
+ int upper,
+ int page_size)
{
+ upper = MAX (upper, page_size);
+ value = MAX (0, value);
+ value = MIN (value, upper - page_size);
+
g_signal_handlers_block_by_func (self->adjustment[orientation],
gtk_grid_view_adjustment_value_changed_cb,
self);
gtk_adjustment_configure (self->adjustment[orientation],
+ gtk_grid_view_adjustment_is_flipped (self, orientation)
+ ? value = upper - page_size - value
+ : value,
0,
- 0,
- 0,
- 0,
- 0,
- 0);
+ upper,
+ page_size * 0.1,
+ page_size * 0.9,
+ page_size);
g_signal_handlers_unblock_by_func (self->adjustment[orientation],
gtk_grid_view_adjustment_value_changed_cb,
self);
+
+ return value;
+}
+
+static int
+gtk_grid_view_update_adjustment (GtkGridView *self,
+ GtkOrientation orientation)
+{
+ int value, page_size, cell_size, total_size;
+ guint anchor_pos;
+
+ anchor_pos = gtk_list_item_tracker_get_position (self->item_manager, self->anchor);
+ if (anchor_pos == GTK_INVALID_LIST_POSITION)
+ {
+ gtk_grid_view_update_adjustment_with_values (self, orientation, 0, 0, 0);
+ return 0;
+ }
+
+ page_size = gtk_widget_get_size (GTK_WIDGET (self), orientation);
+
+ if (self->orientation == orientation)
+ {
+ Cell *cell;
+ CellAugment *aug;
+
+ cell = gtk_list_item_manager_get_root (self->item_manager);
+ g_assert (cell);
+ aug = gtk_list_item_manager_get_item_augment (self->item_manager, cell);
+ if (!gtk_grid_view_get_size_at_position (self,
+ anchor_pos,
+ &value,
+ &cell_size))
+ {
+ g_assert_not_reached ();
+ }
+ if (!self->anchor_ystart)
+ value += cell_size;
+
+ value = gtk_grid_view_update_adjustment_with_values (self,
+ self->orientation,
+ value - self->anchor_yalign * page_size,
+ aug->size,
+ page_size);
+ }
+ else
+ {
+ guint i = anchor_pos % self->n_columns;
+
+ if (self->anchor_xstart)
+ value = ceil (self->column_width * i);
+ else
+ value = ceil (self->column_width * (i + 1));
+ total_size = round (self->n_columns * self->column_width);
+
+ value = gtk_grid_view_update_adjustment_with_values (self,
+ OPPOSITE_ORIENTATION (self->orientation),
+ value - self->anchor_xalign * page_size,
+ total_size,
+ page_size);
+ }
+
+ return value;
}
static int
@@ -415,7 +835,7 @@ gtk_grid_view_size_allocate (GtkWidget *widget,
GtkGridView *self = GTK_GRID_VIEW (widget);
Cell *cell, *start;
GArray *heights;
- int unknown_height, row_height, col_min, col_nat;
+ int row_height, col_min, col_nat;
GtkOrientation opposite_orientation;
gboolean known;
int x, y;
@@ -477,7 +897,7 @@ gtk_grid_view_size_allocate (GtkWidget *widget,
cell_set_size (start, start->size + row_height);
/* step 3: determine height of rows with only unknown items */
- unknown_height = gtk_grid_view_get_unknown_row_size (self, heights);
+ self->unknown_row_height = gtk_grid_view_get_unknown_row_size (self, heights);
g_array_free (heights, TRUE);
i = 0;
@@ -493,29 +913,25 @@ gtk_grid_view_size_allocate (GtkWidget *widget,
if (i >= self->n_columns)
{
if (!known)
- cell_set_size (start, start->size + unknown_height);
+ cell_set_size (start, start->size + self->unknown_row_height);
i -= self->n_columns;
known = FALSE;
if (i >= self->n_columns)
{
- cell_set_size (cell, cell->size + unknown_height * (i / self->n_columns));
+ cell_set_size (cell, cell->size + self->unknown_row_height * (i / self->n_columns));
i %= self->n_columns;
}
start = cell;
}
}
if (i > 0 && !known)
- cell_set_size (start, start->size + unknown_height);
+ cell_set_size (start, start->size + self->unknown_row_height);
/* step 4: update the adjustments */
- gtk_grid_view_update_adjustments (self, GTK_ORIENTATION_HORIZONTAL);
- gtk_grid_view_update_adjustments (self, GTK_ORIENTATION_VERTICAL);
-
- /* step 5: actually allocate the widgets */
- x = - round (gtk_adjustment_get_value (self->adjustment[opposite_orientation]));
- y = - round (gtk_adjustment_get_value (self->adjustment[self->orientation]));
+ x = - gtk_grid_view_update_adjustment (self, opposite_orientation);
+ y = - gtk_grid_view_update_adjustment (self, self->orientation);
i = 0;
row_height = 0;
@@ -550,9 +966,9 @@ gtk_grid_view_size_allocate (GtkWidget *widget,
if (i > self->n_columns)
{
guint unknown_rows = (i - 1) / self->n_columns;
- int unknown_height2 = unknown_rows * unknown_height;
- row_height -= unknown_height2;
- y += unknown_height2;
+ int unknown_height = unknown_rows * self->unknown_row_height;
+ row_height -= unknown_height;
+ y += unknown_height;
i %= self->n_columns;
}
}
@@ -992,7 +1408,7 @@ gtk_grid_view_set_model (GtkGridView *self,
selection_model = GTK_SELECTION_MODEL (gtk_single_selection_new (model));
gtk_list_item_manager_set_model (self->item_manager, selection_model);
- gtk_grid_view_set_anchor (self, 0, 0.0);
+ gtk_grid_view_set_anchor (self, 0, 0.0, TRUE, 0.0, TRUE);
g_object_unref (selection_model);
}
@@ -1082,7 +1498,10 @@ gtk_grid_view_set_max_columns (GtkGridView *self,
gtk_grid_view_set_anchor (self,
gtk_list_item_tracker_get_position (self->item_manager, self->anchor),
- self->anchor_align);
+ self->anchor_xalign,
+ self->anchor_xstart,
+ self->anchor_yalign,
+ self->anchor_ystart);
gtk_widget_queue_resize (GTK_WIDGET (self));
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