pixbuf-renderer.c

Gqview,Linux下基于GTK+库写成的轻量级而能丰富的图像浏览程序。

	pr_queue(pr, 0, 0, pr->width, pr->height, TRUE, TILE_RENDER_ALL, new_data, FALSE);
}

/*
 *-------------------------------------------------------------------
 * signal emission
 *-------------------------------------------------------------------
 */

static void pr_update_signal(PixbufRenderer *pr)
{
#if 0
	printf("FIXME: send updated signal\n");
#endif
}

static void pr_zoom_signal(PixbufRenderer *pr)
{
	g_signal_emit(pr, signals[SIGNAL_ZOOM], 0, pr->zoom);
}

static void pr_clicked_signal(PixbufRenderer *pr, GdkEventButton *bevent)
{
	g_signal_emit(pr, signals[SIGNAL_CLICKED], 0, bevent);
}

static void pr_scroll_notify_signal(PixbufRenderer *pr)
{
	g_signal_emit(pr, signals[SIGNAL_SCROLL_NOTIFY], 0);
}

static void pr_render_complete_signal(PixbufRenderer *pr)
{
	if (!pr->complete)
		{
		g_signal_emit(pr, signals[SIGNAL_RENDER_COMPLETE], 0);
		g_object_set(G_OBJECT(pr), "complete", TRUE, NULL);
		}
}

/*
 *-------------------------------------------------------------------
 * sync and clamp
 *-------------------------------------------------------------------
 */

static gint pr_scroll_clamp(PixbufRenderer *pr)
{
	gint old_xs;
	gint old_ys;

	if (pr->zoom == 0.0)
		{
		pr->x_scroll = 0;
		pr->y_scroll = 0;

		return FALSE;
		}

	old_xs = pr->x_scroll;
	old_ys = pr->y_scroll;

	if (pr->x_offset > 0)
		{
		pr->x_scroll = 0;
		}
	else
		{
		pr->x_scroll = CLAMP(pr->x_scroll, 0, pr->width - pr->vis_width);
		}

	if (pr->y_offset > 0)
		{
		pr->y_scroll = 0;
		}
	else
		{
		pr->y_scroll = CLAMP(pr->y_scroll, 0, pr->height - pr->vis_height);
		}

	return (old_xs != pr->x_scroll || old_ys != pr->y_scroll);
}

static gint pr_size_clamp(PixbufRenderer *pr)
{
	gint old_vw, old_vh;

	old_vw = pr->vis_width;
	old_vh = pr->vis_height;

	if (pr->width < pr->window_width)
		{
		pr->vis_width = pr->width;
		pr->x_offset = (pr->window_width - pr->width) / 2;
		}
	else
		{
		pr->vis_width = pr->window_width;
		pr->x_offset = 0;
		}

	if (pr->height < pr->window_height)
		{
		pr->vis_height = pr->height;
		pr->y_offset = (pr->window_height - pr->height) / 2;
		}
	else
		{
		pr->vis_height = pr->window_height;
		pr->y_offset = 0;
		}

	return (old_vw != pr->vis_width || old_vh != pr->vis_height);
}

static gint pr_zoom_clamp(PixbufRenderer *pr, gdouble zoom,
			  gint force, gint new, gint invalidate,
			  gint *redrawn)
{
	gint w, h;
	gdouble scale;
	gint invalid;

	zoom = CLAMP(zoom, pr->zoom_min, pr->zoom_max);

	if (pr->zoom == zoom && !force) return FALSE;

	w = pr->image_width;
	h = pr->image_height;

	if (zoom == 0.0 && !pr->pixbuf)
		{
		scale = 1.0;
		}
	else if (zoom == 0.0)
		{
		gint max_w;
		gint max_h;
		gint sizeable;

		sizeable = (new && pr_parent_window_sizable(pr));

		if (sizeable)
			{
			max_w = gdk_screen_width();
			max_h = gdk_screen_height();

			if (pr->window_limit)
				{
				max_w = max_w * pr->window_limit_size / 100;
				max_h = max_h * pr->window_limit_size / 100;
				}
			}
		else
			{
			max_w = pr->window_width;
			max_h = pr->window_height;
			}

		if ((pr->zoom_expand && !sizeable) || w > max_w || h > max_h)
			{
			if ((gdouble)max_w / w > (gdouble)max_h / h)
				{
				scale = (gdouble)max_h / h;
				h = max_h;
				w = w * scale + 0.5;
				if (w > max_w) w = max_w;
				}
			else
				{
				scale = (gdouble)max_w / w;
				w = max_w;
				h = h * scale + 0.5;
				if (h > max_h) h = max_h;
				}
			if (w < 1) w = 1;
			if (h < 1) h = 1;
			}
		else
			{
			scale = 1.0;
			}
		}
	else if (zoom > 0.0) /* zoom orig, in */
		{
		scale = zoom;
		w = w * scale;
		h = h * scale;
		}
	else /* zoom out */
		{
		scale = 1.0 / (0.0 - zoom);
		w = w * scale;
		h = h * scale;
		}

	invalid = (pr->width != w || pr->height != h);

	pr->zoom = zoom;
	pr->width = w;
	pr->height = h;
	pr->scale = scale;

	if (invalidate || invalid)
		{
		pr_tile_invalidate_all(pr);
		pr_redraw(pr, TRUE);
		}
	if (redrawn) *redrawn = (invalidate || invalid);

	return TRUE;
}

static void pr_zoom_sync(PixbufRenderer *pr, gdouble zoom,
			 gint force, gint blank, gint new,
			 gint center_point, gint px, gint py)
{
	gdouble old_scale;
	gint old_cx, old_cy;
	gint clamped;
	gint sized;
	gint redrawn = FALSE;

	old_scale = pr->scale;
	if (center_point)
		{
		px = CLAMP(px, 0, pr->width);
		py = CLAMP(py, 0, pr->height);
		old_cx = pr->x_scroll + (px - pr->x_offset);
		old_cy = pr->y_scroll + (py - pr->y_offset);
		}
	else
		{
		px = py = 0;
		old_cx = pr->x_scroll + pr->vis_width / 2;
		old_cy = pr->y_scroll + pr->vis_height / 2;
		}

	if (!pr_zoom_clamp(pr, zoom, force, new, force, &redrawn)) return;

	clamped = pr_size_clamp(pr);
	sized = pr_parent_window_resize(pr, pr->width, pr->height);

	if (force)
		{
		switch (pr->scroll_reset)
			{
			case PR_SCROLL_RESET_NOCHANGE:
				/* maintain old scroll position, do nothing */
				break;
			case PR_SCROLL_RESET_CENTER:
				/* center new image */
				pr->x_scroll = ((double)pr->image_width / 2.0 * pr->scale) - pr->vis_width / 2;
				pr->y_scroll = ((double)pr->image_height / 2.0 * pr->scale) - pr->vis_height / 2;
				break;
			case PR_SCROLL_RESET_TOPLEFT:
			default:
				/* reset to upper left */
				pr->x_scroll = 0;
				pr->y_scroll = 0;
				break;
			}
		}
	else
		{
		/* user zoom does not force, so keep visible center point */
		if (center_point)
			{
			pr->x_scroll = old_cx / old_scale * pr->scale - (px - pr->x_offset);
			pr->y_scroll = old_cy / old_scale * pr->scale - (py - pr->y_offset);
			}
		else
			{
			pr->x_scroll = old_cx / old_scale * pr->scale - (pr->vis_width / 2);
			pr->y_scroll = old_cy / old_scale * pr->scale - (pr->vis_height / 2);
			}
		}

	pr_scroll_clamp(pr);

#if 0
	pr_tile_sync(pr, blank);
#endif

	/* If the window was not sized, redraw the image - we know there will be no size/expose signal.
	 * But even if a size is claimed, there is no guarantee that the window manager will allow it,
	 * so redraw the window anyway :/
	 */
	if (sized || clamped) pr_border_clear(pr);
	pr_redraw(pr, redrawn);

	pr_scroll_notify_signal(pr);
	pr_zoom_signal(pr);
	pr_update_signal(pr);
}

static void pr_size_sync(PixbufRenderer *pr, gint new_width, gint new_height)
{
	gint zoom_changed = FALSE;

	if (pr->window_width == new_width && pr->window_height == new_height) return;

	pr->window_width = new_width;
	pr->window_height = new_height;

	if (pr->zoom == 0.0)
		{
		gdouble old_scale = pr->scale;
		pr_zoom_clamp(pr, 0.0, TRUE, FALSE, FALSE, NULL);
		zoom_changed = (old_scale != pr->scale);
		}

	pr_size_clamp(pr);
	pr_scroll_clamp(pr);

	/* ensure scroller remains visible */
	if (pr->scroller_overlay != -1)
		{
		gint update = FALSE;

		if (pr->scroller_x > new_width)
			{
			pr->scroller_x = new_width;
			pr->scroller_xpos = new_width;
			update = TRUE;
			}
		if (pr->scroller_y > new_height)
			{
			pr->scroller_y = new_height;
			pr->scroller_ypos = new_height;
			update = TRUE;
			}

		if (update)
			{
			GdkPixbuf *pixbuf;

			if (pixbuf_renderer_overlay_get(pr, pr->scroller_overlay, &pixbuf, NULL, NULL))
				{
				gint w, h;

				w = gdk_pixbuf_get_width(pixbuf);
				h = gdk_pixbuf_get_height(pixbuf);
				pixbuf_renderer_overlay_set(pr, pr->scroller_overlay, pixbuf,
							    pr->scroller_x - w / 2, pr->scroller_y - h / 2);
				}
			}
		}

	pr_border_clear(pr);

#if 0
	pr_tile_sync(pr, pr->width, pr->height, FALSE);
#endif

	pr_scroll_notify_signal(pr);
	if (zoom_changed) pr_zoom_signal(pr);
	pr_update_signal(pr);
}

static void pr_size_cb(GtkWidget *widget, GtkAllocation *allocation, gpointer data)
{
	PixbufRenderer *pr = data;

	pr_size_sync(pr, allocation->width, allocation->height);
}

static void pixbuf_renderer_paint(PixbufRenderer *pr, GdkRectangle *area)
{
	gint x, y;

	pr_border_draw(pr, area->x, area->y, area->width, area->height);

	x = MAX(0, (gint)area->x - pr->x_offset + pr->x_scroll);
	y = MAX(0, (gint)area->y - pr->y_offset + pr->y_scroll);

	pr_queue(pr, x, y,
		 MIN((gint)area->width, pr->width - x),
		 MIN((gint)area->height, pr->height - y),
		 FALSE, TILE_RENDER_ALL, FALSE, FALSE);
}

/*
 *-------------------------------------------------------------------
 * scrolling
 *-------------------------------------------------------------------
 */

void pixbuf_renderer_scroll(PixbufRenderer *pr, gint x, gint y)
{
	gint old_x, old_y;
	gint x_off, y_off;
	gint w, h;

	g_return_if_fail(IS_PIXBUF_RENDERER(pr));

	if (!pr->pixbuf && !pr->source_tiles_enabled) return;

	old_x = pr->x_scroll;
	old_y = pr->y_scroll;

	pr->x_scroll += x;
	pr->y_scroll += y;

	pr_scroll_clamp(pr);
	if (pr->x_scroll == old_x && pr->y_scroll == old_y) return;

	pr_scroll_notify_signal(pr);

	if (pr->overlay_list)
		{
		gint new_x, new_y;

		new_x = pr->x_scroll;
		new_y = pr->y_scroll;
		pr->x_scroll = old_x;
		pr->y_scroll = old_y;

		pr_overlay_queue_all(pr);

		pr->x_scroll = new_x;
		pr->y_scroll = new_y;
		}

	x_off = pr->x_scroll - old_x;
	y_off = pr->y_scroll - old_y;

	w = pr->vis_width - abs(x_off);
	h = pr->vis_height - abs(y_off);

	if (w < 1 || h < 1)
		{
		/* scrolled completely to new material */
		pr_queue(pr, 0, 0, pr->width, pr->height, TRUE, TILE_RENDER_ALL, FALSE, FALSE);
		return;
		}
	else
		{
		gint x1, y1;
		gint x2, y2;
		GtkWidget *box;
		GdkGC *gc;

		if (x_off < 0)
			{
			x1 = abs(x_off);
			x2 = 0;
			}
		else
			{
			x1 = 0;
			x2 = abs(x_off);
			}

		if (y_off < 0)
			{
			y1 = abs(y_off);
			y2 = 0;
			}
		else
			{
			y1 = 0;
			y2 = abs(y_off);
			}

		box = GTK_WIDGET(pr);

		gc = gdk_gc_new(box->window);
		gdk_gc_set_exposures(gc, TRUE);
		gdk_draw_drawable(box->window, gc,
				  box->window,
				  x2 + pr->x_offset, y2 + pr->y_offset,
				  x1 + pr->x_offset, y1 + pr->y_offset, w, h);
		g_object_unref(gc);

		if (pr->overlay_list)
			{
			pr_overlay_queue_all(pr);
			}

		w = pr->vis_width - w;
		h = pr->vis_height - h;

		if (w > 0)
			{
			pr_queue(pr,
				 x_off > 0 ? pr->x_scroll + (pr->vis_width - w) : pr->x_scroll, pr->y_scroll,
				 w, pr->vis_height, TRUE, TILE_RENDER_ALL, FALSE, FALSE);
			}
		if (h > 0)
			{
			/* FIXME, to optimize this, remove overlap */
			pr_queue(pr,
				 pr->x_scroll, y_off > 0 ? pr->y_scroll + (pr->vis_height - h) : pr->y_scroll,
				 pr->vis_width, h, TRUE, TILE_RENDER_ALL, FALSE, FALSE);
			}
		}
}

void pixbuf_renderer_scroll_to_point(PixbufRenderer *pr, gint x, gint y,
				     gdouble x_align, gdouble y_align)
{
	gint px, py;
	gint ax, ay;

	x_align = CLAMP(x_align, 0.0, 1.0);
	y_align = CLAMP(y_align, 0.0, 1.0);

	ax = (gdouble)pr->vis_width * x_align;
	ay = (gdouble)pr->vis_height * y_align;

	px = (gdouble)x * pr->scale - (pr->x_scroll + ax);
	py = (gdouble)y * pr->scale - (pr->y_scroll + ay);

	pixbuf_renderer_scroll(pr, px, py);
}

/*
 *-------------------------------------------------------------------
 * mouse
 *-------------------------------------------------------------------
 */

static gint pr_mouse_motion_cb(GtkWidget *widget, GdkEventButton *bevent, gpointer data)
{
	PixbufRenderer *pr;
	gint accel;

	pr = PIXBUF_RENDERER(widget);

	if (pr->scroller_id != -1)
		{
		pr->scroller_xpos = bevent->x;
		pr->scroller_ypos = bevent->y;
		}

	if (!pr->in_drag || !gdk_pointer_is_grabbed()) return FALSE;

	if (pr->drag_moved < PR_DRAG_SCROLL_THRESHHOLD)
		{
		pr->drag_moved++;
		}
	else
		{
		widget_set_cursor(widget, GDK_FLEUR);
		}

	if (bevent->state & GDK_SHIFT_MASK)
		{
		accel = PR_PAN_SHIFT_MULTIPLIER;
		}
	else
		{
		accel = 1;
		}

	/* do the scroll */
	pixbuf_renderer_scroll(pr, (pr->drag_last_x - bevent->x) * accel,
			       (pr->drag_last_y - bevent->y) * accel);

	pr->drag_last_x = bevent->x;
	pr->drag_last_y = bevent->y;

	return FALSE;
}

static gint pr_mouse_press_cb(GtkWidget *widget, GdkEventButton *bevent, gpointer data)
{
	PixbufRenderer *pr;
	GtkWidget *parent;

	pr = PIXBUF_RENDERER(widget);

	if (pr->scroller_id != -1) return TRUE;

	switch (bevent->button)
		{
		case 1:
			pr->in_drag = TRUE;
			pr->d