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Diffstat (limited to 'trunk/pango/pangocairo-context.c')
| -rw-r--r-- | trunk/pango/pangocairo-context.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/trunk/pango/pangocairo-context.c b/trunk/pango/pangocairo-context.c new file mode 100644 index 00000000..98558f89 --- /dev/null +++ b/trunk/pango/pangocairo-context.c @@ -0,0 +1,438 @@ +/* Pango + * pangocairo-fontmap.c: Cairo font handling + * + * Copyright (C) 2000-2005 Red Hat Software + * + * 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 <config.h> + +#include "pangocairo.h" +#include "pangocairo-private.h" +#include "pango-impl-utils.h" + +#include <string.h> + +typedef struct _PangoCairoContextInfo PangoCairoContextInfo; + +struct _PangoCairoContextInfo +{ + double dpi; + + cairo_font_options_t *set_options; + cairo_font_options_t *surface_options; + cairo_font_options_t *merged_options; + + PangoCairoShapeRendererFunc shape_renderer_func; + gpointer shape_renderer_data; + GDestroyNotify shape_renderer_notify; +}; + +static void +free_context_info (PangoCairoContextInfo *info) +{ + if (info->set_options) + cairo_font_options_destroy (info->set_options); + if (info->surface_options) + cairo_font_options_destroy (info->surface_options); + if (info->merged_options) + cairo_font_options_destroy (info->merged_options); + + if (info->shape_renderer_notify) + info->shape_renderer_notify (info->shape_renderer_data); + + g_slice_free (PangoCairoContextInfo, info); +} + +static PangoCairoContextInfo * +get_context_info (PangoContext *context, + gboolean create) +{ + static GQuark context_info_quark; + PangoCairoContextInfo *info; + + if (G_UNLIKELY (!context_info_quark)) + context_info_quark = g_quark_from_static_string ("pango-cairo-context-info"); + + info = g_object_get_qdata (G_OBJECT (context), context_info_quark); + + if (G_UNLIKELY (!info) && create) + { + info = g_slice_new0 (PangoCairoContextInfo); + info->dpi = -1.0; + + g_object_set_qdata_full (G_OBJECT (context), context_info_quark, + info, (GDestroyNotify)free_context_info); + } + + return info; +} + +static gboolean +_pango_cairo_update_context (cairo_t *cr, + PangoContext *context) +{ + PangoCairoContextInfo *info; + cairo_matrix_t cairo_matrix; + cairo_surface_t *target; + PangoMatrix pango_matrix; + const PangoMatrix *layout_matrix, identity_matrix = PANGO_MATRIX_INIT; + gboolean changed = FALSE; + + info = get_context_info (context, TRUE); + + cairo_get_matrix (cr, &cairo_matrix); + pango_matrix.xx = cairo_matrix.xx; + pango_matrix.yx = cairo_matrix.yx; + pango_matrix.xy = cairo_matrix.xy; + pango_matrix.yy = cairo_matrix.yy; + pango_matrix.x0 = cairo_matrix.x0; + pango_matrix.y0 = cairo_matrix.y0; + + layout_matrix = pango_context_get_matrix (context); + if (!layout_matrix) + layout_matrix = &identity_matrix; + + if (0 != memcmp (&pango_matrix, layout_matrix, sizeof (pango_matrix))) + changed = TRUE; + + pango_context_set_matrix (context, &pango_matrix); + + + target = cairo_get_target (cr); + + if (!info->surface_options) { + info->surface_options = cairo_font_options_create (); + changed = TRUE; + cairo_surface_get_font_options (target, info->surface_options); + } else { + cairo_font_options_t *surface_options = cairo_font_options_create (); + cairo_surface_get_font_options (target, surface_options); + if (!cairo_font_options_equal (surface_options, info->surface_options)) + { + cairo_surface_get_font_options (target, info->surface_options); + changed = TRUE; + } + cairo_font_options_destroy (surface_options); + } + + if (info->merged_options) + { + cairo_font_options_destroy (info->merged_options); + info->merged_options = NULL; + } + + return changed; +} + +/** + * pango_cairo_update_context: + * @cr: a Cairo context + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * + * Updates a #PangoContext previously created for use with Cairo to + * match the current transformation and target surface of a Cairo + * context. If any layouts have been created for the context, + * it's necessary to call pango_layout_context_changed() on those + * layouts. + * + * Since: 1.10 + **/ +void +pango_cairo_update_context (cairo_t *cr, + PangoContext *context) +{ + g_return_if_fail (cr != NULL); + g_return_if_fail (PANGO_IS_CONTEXT (context)); + + (void) _pango_cairo_update_context (cr, context); +} + +/** + * pango_cairo_context_set_resolution: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * @dpi: the resolution in "dots per inch". (Physical inches aren't actually + * involved; the terminology is conventional.) A 0 or negative value + * means to use the resolution from the font map. + * + * Sets the resolution for the context. This is a scale factor between + * points specified in a #PangoFontDescription and Cairo units. The + * default value is 96, meaning that a 10 point font will be 13 + * units high. (10 * 96. / 72. = 13.3). + * + * Since: 1.10 + **/ +void +pango_cairo_context_set_resolution (PangoContext *context, + double dpi) +{ + PangoCairoContextInfo *info = get_context_info (context, TRUE); + info->dpi = dpi; +} + +/** + * pango_cairo_context_get_resolution: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * + * Gets the resolution for the context. See pango_cairo_context_set_resolution() + * + * Return value: the resolution in "dots per inch". A negative value will + * be returned if no resolution has previously been set. + * + * Since: 1.10 + **/ +double +pango_cairo_context_get_resolution (PangoContext *context) +{ + PangoCairoContextInfo *info = get_context_info (context, FALSE); + + if (info) + return info->dpi; + else + return -1.0; +} + +/** + * pango_cairo_context_set_font_options: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * @options: a #cairo_font_options_t, or %NULL to unset any previously set + * options. A copy is made. + * + * Sets the font options used when rendering text with this context. + * These options override any options that pango_cairo_update_context() + * derives from the target surface. + */ +void +pango_cairo_context_set_font_options (PangoContext *context, + const cairo_font_options_t *options) +{ + PangoCairoContextInfo *info; + + g_return_if_fail (PANGO_IS_CONTEXT (context)); + + info = get_context_info (context, TRUE); + + if (info->set_options) + cairo_font_options_destroy (info->set_options); + + if (options) + info->set_options = cairo_font_options_copy (options); + else + info->set_options = NULL; + + if (info->merged_options) + { + cairo_font_options_destroy (info->merged_options); + info->merged_options = NULL; + } +} + +/** + * pango_cairo_context_get_font_options: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * + * Retrieves any font rendering options previously set with + * pango_cairo_font_map_set_font_options(). This functions not report options + * that are derived from the target surface by pango_cairo_update_context() + * + * Return value: the font options previously set on the context, or %NULL + * if no options have been set. This value is owned by the context + * and must not be modified or freed. + **/ +G_CONST_RETURN cairo_font_options_t * +pango_cairo_context_get_font_options (PangoContext *context) +{ + PangoCairoContextInfo *info; + + g_return_val_if_fail (PANGO_IS_CONTEXT (context), NULL); + + info = get_context_info (context, FALSE); + + if (info) + return info->set_options; + else + return NULL; +} + +/** + * _pango_cairo_context_merge_font_options: + * @context: a #PangoContext + * @options: a #cairo_font_options_t + * + * Merge together options from the target surface and explicitly set + * on the context. + * + * Return value: the combined set of font options. This value is owned + * by the context and must not be modified or freed. + **/ +G_CONST_RETURN cairo_font_options_t * +_pango_cairo_context_get_merged_font_options (PangoContext *context) +{ + PangoCairoContextInfo *info = get_context_info (context, TRUE); + + if (!info->merged_options) + { + info->merged_options = cairo_font_options_create (); + + if (info->surface_options) + cairo_font_options_merge (info->merged_options, info->surface_options); + if (info->set_options) + cairo_font_options_merge (info->merged_options, info->set_options); + } + + return info->merged_options; +} + +/** + * pango_cairo_context_set_shape_renderer: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * @func: Callback function for rendering attributes of type + * %PANGO_ATTR_SHAPE, or %NULL to disable shape rendering. + * @data: User data that will be passed to @func. + * @dnotify: Callback that will be called when the + * context is freed to release @data, or %NULL. + * + * Sets callback function for context to use for rendering attributes + * of type %PANGO_ATTR_SHAPE. See #PangoCairoShapeRendererFunc for + * details. + * + * Since: 1.18 + */ +void +pango_cairo_context_set_shape_renderer (PangoContext *context, + PangoCairoShapeRendererFunc func, + gpointer data, + GDestroyNotify dnotify) +{ + PangoCairoContextInfo *info; + + g_return_if_fail (PANGO_IS_CONTEXT (context)); + + info = get_context_info (context, TRUE); + + if (info->shape_renderer_notify) + info->shape_renderer_notify (info->shape_renderer_data); + + info->shape_renderer_func = func; + info->shape_renderer_data = data; + info->shape_renderer_notify = dnotify; +} + +/** + * pango_cairo_context_get_shape_renderer: + * @context: a #PangoContext, from pango_cairo_font_map_create_context() + * @data: Pointer to #gpointer to return user data + * + * Sets callback function for context to use for rendering attributes + * of type %PANGO_ATTR_SHAPE. See #PangoCairoShapeRendererFunc for + * details. + * + * Retrieves callback function and associated user data for rendering + * attributes of type %PANGO_ATTR_SHAPE as set by + * pango_cairo_context_set_shape_renderer(), if any. + * + * Return value: the shape rendering callback previously set on the context, or %NULL + * if no shape rendering callback have been set. + * + * Since: 1.18 + */ +PangoCairoShapeRendererFunc +pango_cairo_context_get_shape_renderer (PangoContext *context, + gpointer *data) +{ + PangoCairoContextInfo *info; + + g_return_val_if_fail (PANGO_IS_CONTEXT (context), NULL); + + info = get_context_info (context, FALSE); + + if (info) + { + if (data) + *data = info->shape_renderer_data; + return info->shape_renderer_func; + } + else + { + if (data) + *data = NULL; + return NULL; + } +} + +/** + * pango_cairo_create_layout: + * @cr: a Cairo context + * + * Creates a layout object set up to match the current transformation + * and target surface of the Cairo context. This layout can then be + * used for text measurement with functions like + * pango_layout_get_size() or drawing with functions like + * pango_cairo_show_layout(). If you change the transformation + * or target surface for @cr, you need to call pango_cairo_update_layout() + * + * This function is the most convenient way to use Cairo with Pango, + * however it is slightly inefficient since it creates a separate + * #PangoContext object for each layout. This might matter in an + * application that was laying out large amounts of text. + * + * Return value: the newly created #PangoLayout. Free with + * g_object_unref(). + * + * Since: 1.10 + **/ +PangoLayout * +pango_cairo_create_layout (cairo_t *cr) +{ + PangoFontMap *fontmap; + PangoContext *context; + PangoLayout *layout; + + g_return_val_if_fail (cr != NULL, NULL); + + fontmap = pango_cairo_font_map_get_default (); + context = pango_cairo_font_map_create_context ((PangoCairoFontMap *) (fontmap)); + layout = pango_layout_new (context); + + pango_cairo_update_context (cr, context); + g_object_unref (context); + + return layout; +} + +/** + * pango_cairo_update_layout: + * @cr: a Cairo context + * @layout: a #PangoLayout, from pango_cairo_create_layout() + * + * Updates the private #PangoContext of a #PangoLayout created with + * pango_cairo_create_layout() to match the current transformation + * and target surface of a Cairo context. + * + * Since: 1.10 + **/ +void +pango_cairo_update_layout (cairo_t *cr, + PangoLayout *layout) +{ + g_return_if_fail (cr != NULL); + g_return_if_fail (PANGO_IS_LAYOUT (layout)); + + if (_pango_cairo_update_context (cr, pango_layout_get_context (layout))) + pango_layout_context_changed (layout); +} + |