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Diffstat (limited to 'docs/pango_layout.md')
| -rw-r--r-- | docs/pango_layout.md | 100 |
1 files changed, 54 insertions, 46 deletions
diff --git a/docs/pango_layout.md b/docs/pango_layout.md index a4d8e122..e723c659 100644 --- a/docs/pango_layout.md +++ b/docs/pango_layout.md @@ -4,75 +4,74 @@ Title: Complex layout # Complex layout -The central object in high-level Pango API is [class@Pango.Layout]. +The central object in high-level Pango API is [class@Pango2.Layout]. It is well-suited for breaking text into lines that fill a rectangular area, since that is commonly how paragraphs are formatted in books. But in real-life situations, text does not always fit in a box. Examples of more complicated requirements are fitting text around an image, or flowing text between multiple frames. -For cases like these, it is better to use [class@Pango.LineBreaker] -directly instead of `PangoLayout` (`PangoLayout` is using a line -breaker internally). The way `PangoLineBreaker` works is to let +For cases like these, it is better to use [class@Pango2.LineBreaker] +directly instead of `Pango2Layout` (`Pango2Layout` is using a line +breaker internally). The way `Pango2LineBreaker` works is to let applications access the formatted result one line at a time, place it, and change parameters such as the line width before requesting the next one. -The following example shows how to use `PangoLineBreaker` to +The following example shows how to use `Pango2LineBreaker` to produce an unusually shaped paragraph with a hole in the middle. -## Using GtkLineBreaker +## Using Pango2LineBreaker ``` -#include <pango/pango.h> -#include <pango/pangocairo.h> +#include <pango2/pangocairo.h> -static PangoLines * +static Pango2Lines * format_text (const char *text) { - PangoContext *context; - PangoLineBreaker *breaker; - PangoLines *lines; + Pango2Context *context; + Pango2LineBreaker *breaker; + Pango2Lines *lines; int x, y, width; int inc, m, w, w2; - context = pango_font_map_create_context (pango_font_map_get_default ()); - breaker = pango_line_breaker_new (context); + context = pango2_context_new (); + breaker = pango2_line_breaker_new (context); - pango_line_breaker_add_text (breaker, text, -1, NULL); + pango2_line_breaker_add_text (breaker, text, -1, NULL); - lines = pango_lines_new (); + lines = pango2_lines_new (); m = 200; w = 10; w2 = -200; inc = 40; - y = 40 * PANGO_SCALE; - x = (m - w / 2) * PANGO_SCALE; - width = w * PANGO_SCALE; + y = 40 * PANGO2_SCALE; + x = (m - w / 2) * PANGO2_SCALE; + width = w * PANGO2_SCALE; - while (pango_line_breaker_has_line (breaker)) + while (pango2_line_breaker_has_line (breaker)) { - PangoLine *line; - PangoRectangle ext; + Pango2Line *line; + Pango2Rectangle ext; gboolean ltr; - line = pango_line_breaker_next_line (breaker, + line = pango2_line_breaker_next_line (breaker, x, width, - PANGO_WRAP_CHAR, - PANGO_ELLIPSIZE_NONE); + PANGO2_WRAP_CHAR, + PANGO2_ELLIPSIZE_NONE); - pango_line_get_extents (line, NULL, &ext); - line = pango_line_justify (line, width); - pango_lines_add_line (lines, line, x, y - ext.y); + pango2_line_get_extents (line, NULL, &ext); + line = pango2_line_justify (line, width); + pango2_lines_add_line (lines, line, x, y - ext.y); - ltr = pango_line_breaker_get_direction (breaker) == PANGO_DIRECTION_LTR; + ltr = pango2_line_breaker_get_direction (breaker) == PANGO2_DIRECTION_LTR; - if (w2 > 0 && ltr && x <= m * PANGO_SCALE) - x = (m + w2 / 2) * PANGO_SCALE; - else if (w2 > 0 && !ltr && x > m * PANGO_SCALE) - x = (m - w2 / 2) * PANGO_SCALE; + if (w2 > 0 && ltr && x <= m * PANGO2_SCALE) + x = (m + w2 / 2) * PANGO2_SCALE; + else if (w2 > 0 && !ltr && x > m * PANGO2_SCALE) + x = (m - w2 / 2) * PANGO2_SCALE; else { y += ext.height; @@ -83,14 +82,14 @@ format_text (const char *text) inc = - inc; if (w2 > 0) - width = ((w - w2) / 2) * PANGO_SCALE; + width = ((w - w2) / 2) * PANGO2_SCALE; else - width = w * PANGO_SCALE; + width = w * PANGO2_SCALE; if (ltr) - x = (m - w / 2) * PANGO_SCALE; + x = (m - w / 2) * PANGO2_SCALE; else - x = (m + w / 2) * PANGO_SCALE; + x = (m + w / 2) * PANGO2_SCALE; } } @@ -101,18 +100,18 @@ format_text (const char *text) } static void -draw_lines (cairo_t *cr, PangoLines *lines) +draw_lines (cairo_t *cr, Pango2Lines *lines) { - for (int i = 0; i < pango_lines_get_line_count (lines); i++) + for (int i = 0; i < pango2_lines_get_line_count (lines); i++) { - PangoLine *line = pango_lines_get_lines (lines)[i]; + Pango2Line *line = pango2_lines_get_lines (lines)[i]; int x, y; - pango_lines_get_line_position (lines, i, &x, &y); + pango2_lines_get_line_position (lines, i, &x, &y); cairo_save (cr); - cairo_move_to (cr, x / (double)PANGO_SCALE, y / (double)PANGO_SCALE); - pango_cairo_show_line (cr, line); + cairo_move_to (cr, x / (double)PANGO2_SCALE, y / (double)PANGO2_SCALE); + pango2_cairo_show_line (cr, line); cairo_restore (cr); } } @@ -121,12 +120,13 @@ int main (int argc, char *argv[]) { const char *filename; - PangoLines *lines; + Pango2Lines *lines; cairo_surface_t *surface; cairo_t *cr; char *text; gsize length; GError *error = NULL; + cairo_status_t status; if (argc != 3) { @@ -152,8 +152,16 @@ main (int argc, char *argv[]) draw_lines (cr, lines); g_object_unref (lines); - cairo_surface_write_to_png (surface, filename); - g_print ("Output written to %s\n", filename); +#ifdef CAIRO_HAS_PNG_FUNCTIONS + status = cairo_surface_write_to_png (surface, filename); +#else + status = CAIRO_STATUS_PNG_ERROR; /* Not technically correct, but... */ +#endif + + if (status != CAIRO_STATUS_SUCCESS) + g_printerr ("Could not save png to '%s'\n", filename); + else + g_print ("Output written to %s\n", filename); cairo_surface_destroy (surface); cairo_destroy (cr); |