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Diffstat (limited to 'examples/cairoview.c')
| -rw-r--r-- | examples/cairoview.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/examples/cairoview.c b/examples/cairoview.c new file mode 100644 index 00000000..ec285432 --- /dev/null +++ b/examples/cairoview.c @@ -0,0 +1,272 @@ +/* Pango + * cairoview.c: Example program to view a UTF-8 encoding file + * using Cairo to render result + * + * Copyright (C) 2005 Red Hat, Inc. + * Copyright (C) 2001 Sun Microsystems + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#include <errno.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include "renderdemo.h" + +#include <pango/pangocairo.h> + +static pixman_region16_t *update_region = NULL; +static PangoContext *context; +static Display *display; +int screen; +static Window window; +gboolean show_borders; + +typedef struct +{ + cairo_t *cr; + int x_offset; + int y_offset; +} RenderData; + +static void +do_cairo_render (PangoLayout *layout, + int x, + int y, + gpointer data) +{ + RenderData *render_data = data; + cairo_t *cr = render_data->cr; + + cairo_move_to (cr, x, y); + pango_cairo_show_layout (cr, layout); + + if (show_borders) + { + PangoRectangle ink, logical; + double lw = cairo_current_line_width (cr); + + pango_layout_get_extents (layout, &ink, &logical); + + cairo_save (cr); + cairo_set_rgb_color (cr, 1.0, 0.0, 0.0); + cairo_set_alpha (cr, 0.75); + + cairo_rectangle (cr, + (double)logical.x / PANGO_SCALE - lw / 2, + (double)logical.y / PANGO_SCALE - lw / 2, + (double)logical.width / PANGO_SCALE + lw, + (double)logical.height / PANGO_SCALE + lw); + cairo_stroke (cr); + + cairo_set_rgb_color (cr, 0.0, 1.0, 0.0); + + cairo_rectangle (cr, + (double)ink.x / PANGO_SCALE - lw / 2, + (double)ink.y / PANGO_SCALE - lw / 2, + (double)ink.width / PANGO_SCALE + lw, + (double)ink.height / PANGO_SCALE + lw); + cairo_stroke (cr); + + cairo_restore (cr); + } +} + +static void +do_cairo_transform (PangoContext *context, + PangoMatrix *matrix, + gpointer data) +{ + RenderData *render_data = data; + cairo_matrix_t *cairo_matrix = cairo_matrix_create (); + + if (matrix) + { + cairo_matrix_set_affine (cairo_matrix, + matrix->xx, matrix->yx, + matrix->xy, matrix->yy, + matrix->x0 + render_data->x_offset, + matrix->y0 + render_data->y_offset); + } + else + { + cairo_matrix_set_affine (cairo_matrix, + 1.0, 0, + 0, 1.0, + render_data->x_offset, + render_data->y_offset); + } + + cairo_set_matrix (render_data->cr, cairo_matrix); + cairo_matrix_destroy (cairo_matrix); + + pango_context_set_matrix (context, matrix); + pango_cairo_update_context (render_data->cr, context); +} + +void +update () +{ + RenderData render_data; + cairo_t *cr; + Pixmap pixmap; + GC gc; + pixman_box16_t *extents; + int n_rects; + pixman_box16_t *rects; + XRectangle *xrects; + int i; + + /* Create a temporary pixmap and a Cairo context pointing to it */ + extents = pixman_region_extents (update_region); + pixmap = XCreatePixmap (display, window, + extents->x2 - extents->x1, + extents->y2 - extents->y1, + DefaultDepth (display, screen)); + + cr = render_data.cr = cairo_create(); + cairo_set_target_drawable (cr, display, pixmap); + render_data.x_offset = - extents->x1; + render_data.y_offset = - extents->y1; + + do_cairo_transform (context, NULL, &render_data); + + /* Clip to the current update region and fill with white */ + n_rects = pixman_region_num_rects (update_region); + rects = pixman_region_rects (update_region); + xrects = g_new (XRectangle, n_rects); + + for (i = 0; i < n_rects; i++) + { + xrects[i].x = rects[i].x1; + xrects[i].y = rects[i].y1; + xrects[i].width = rects[i].x2 - rects[i].x1; + xrects[i].height = rects[i].y2 - rects[i].y1; + + cairo_rectangle (cr, xrects[i].x, xrects[i].y, + xrects[i].width, xrects[i].height); + } + + cairo_clip (cr); + cairo_set_rgb_color (cr, 1.0, 1.0, 1.0); + cairo_fill (cr); + + /* Draw the text in black */ + cairo_set_rgb_color (cr, 0.0, 0.0, 0.0); + do_output (context, do_cairo_render, do_cairo_transform, &render_data, NULL, NULL); + cairo_destroy (cr); + + /* Copy the updated area onto the window */ + gc = XCreateGC (display, pixmap, 0, NULL); + XSetClipRectangles (display, gc, 0, 0, xrects, n_rects, YXBanded); + + XCopyArea (display, pixmap, window, gc, + 0, 0, + extents->x2 - extents->x1, extents->y2 - extents->y1, + extents->x1, extents->y1); + + g_free (xrects); + XFreeGC (display, gc); + XFreePixmap (display, pixmap); + + pixman_region_destroy (update_region); + update_region = NULL; +} + +void +expose (XExposeEvent *xev) +{ + if (!update_region) + update_region = pixman_region_create (); + + pixman_region_union_rect (update_region, update_region, + xev->x, xev->y, xev->width, xev->height); +} + +int main (int argc, char **argv) +{ + PangoFontMap *fontmap; + XEvent xev; + unsigned long bg; + int width, height; + RenderData render_data; + unsigned int quit_keycode; + unsigned int borders_keycode; + + g_type_init(); + + parse_options (argc, argv); + + display = XOpenDisplay (NULL); + if (!display) + fail ("Cannot open display %s\n", XDisplayName (NULL)); + screen = DefaultScreen (display); + + fontmap = pango_cairo_font_map_get_default (); + context = pango_cairo_font_map_create_context (PANGO_CAIRO_FONT_MAP (fontmap)); + + render_data.cr = cairo_create (); + render_data.x_offset = 0; + render_data.y_offset = 0; + do_output (context, NULL, do_cairo_transform, &render_data, &width, &height); + cairo_destroy (render_data.cr); + + bg = WhitePixel (display, screen); + + window = XCreateSimpleWindow (display, DefaultRootWindow (display), + 0, 0, width, height, 0, + bg, bg); + XSelectInput (display, window, ExposureMask | KeyPressMask); + + XMapWindow (display, window); + XmbSetWMProperties (display, window, + get_options_string (), + NULL, NULL, 0, NULL, NULL, NULL); + + borders_keycode = XKeysymToKeycode(display, 'B'); + quit_keycode = XKeysymToKeycode(display, 'Q'); + + while (1) + { + if (!XPending (display) && update_region) + update (); + + XNextEvent (display, &xev); + switch (xev.xany.type) { + case KeyPress: + if (xev.xkey.keycode == quit_keycode) + goto done; + else if (xev.xkey.keycode == borders_keycode) + { + show_borders = !show_borders; + if (!update_region) + update_region = pixman_region_create (); + + pixman_region_union_rect (update_region, update_region, + 0, 0, width, height); + } + break; + case Expose: + expose (&xev.xexpose); + break; + } + } + + done: + return 0; +} |