[PATCH 06/12] editor: Extract text handling into text_layout

[Jan Arne Petersen]

From: Jan Arne Petersen <jpeter...@openismus.com>

Create a text_layout struct and functions for handling simple text
layouts.
---
 clients/editor.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 94 insertions(+), 5 deletions(-)

diff --git a/clients/editor.c b/clients/editor.c
index 540642b..f3b374c 100644
--- a/clients/editor.c
+++ b/clients/editor.c
@@ -32,6 +32,18 @@
 #include "window.h"
 #include "text-client-protocol.h"
 
+static const char *font_name = "sans-serif";
+static int font_size = 14;
+
+struct text_layout {
+       cairo_glyph_t *glyphs;
+       int num_glyphs;
+       cairo_text_cluster_t *clusters;
+       int num_clusters;
+       cairo_text_cluster_flags_t cluster_flags;
+       cairo_scaled_font_t *font;
+};
+
 struct text_entry {
        struct widget *widget;
        struct window *window;
@@ -39,6 +51,7 @@ struct text_entry {
        int active;
        struct rectangle allocation;
        struct text_model *model;
+       struct text_layout *layout;
 };
 
 struct editor {
@@ -50,6 +63,81 @@ struct editor {
        struct text_entry *editor;
 };
 
+static struct text_layout *
+text_layout_create(void)
+{
+       struct text_layout *layout;
+       cairo_surface_t *surface;
+       cairo_t *cr;
+
+       layout = malloc(sizeof *layout);
+       if (!layout)
+               return NULL;
+
+       layout->glyphs = NULL;
+       layout->num_glyphs = 0;
+
+       layout->clusters = NULL;
+       layout->num_clusters = 0;
+
+       surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
+       cr = cairo_create(surface);
+       cairo_set_font_size(cr, font_size);
+       cairo_select_font_face(cr, font_name, CAIRO_FONT_SLANT_NORMAL, 
CAIRO_FONT_WEIGHT_NORMAL);
+       layout->font = cairo_get_scaled_font(cr);
+       cairo_scaled_font_reference(layout->font);
+
+       cairo_destroy(cr);
+       cairo_surface_destroy(surface);
+
+       return layout;
+}
+
+static void
+text_layout_destroy(struct text_layout *layout)
+{
+       if (layout->glyphs)
+               cairo_glyph_free(layout->glyphs);
+
+       if (layout->clusters)
+               cairo_text_cluster_free(layout->clusters);
+
+       cairo_scaled_font_destroy(layout->font);
+
+       free(layout);
+}
+
+static void
+text_layout_set_text(struct text_layout *layout,
+                    const char *text)
+{
+       if (layout->glyphs)
+               cairo_glyph_free(layout->glyphs);
+
+       if (layout->clusters)
+               cairo_text_cluster_free(layout->clusters);
+
+       layout->glyphs = NULL;
+       layout->num_glyphs = 0;
+       layout->clusters = NULL;
+       layout->num_clusters = 0;
+
+       cairo_scaled_font_text_to_glyphs(layout->font, 0, 0, text, -1,
+                                        &layout->glyphs, &layout->num_glyphs,
+                                        &layout->clusters, 
&layout->num_clusters,
+                                        &layout->cluster_flags);
+}
+
+static void
+text_layout_draw(struct text_layout *layout, cairo_t *cr)
+{
+       cairo_save(cr);
+       cairo_set_scaled_font(cr, layout->font);
+       cairo_show_glyphs(cr, layout->glyphs, layout->num_glyphs);
+       cairo_restore(cr);
+}
+
+
 static void text_entry_redraw_handler(struct widget *widget, void *data);
 static void text_entry_button_handler(struct widget *widget,
                                      struct input *input, uint32_t time,
@@ -61,6 +149,7 @@ text_entry_append(struct text_entry *entry, const char *text)
 {
        entry->text = realloc(entry->text, strlen(entry->text) + strlen(text) + 
1);
        strcat(entry->text, text);
+       text_layout_set_text(entry->layout, entry->text);
 }
 
 
@@ -163,6 +252,9 @@ text_entry_create(struct editor *editor, const char *text)
        entry->model = 
text_model_factory_create_text_model(editor->text_model_factory);
        text_model_add_listener(entry->model, &text_model_listener, entry);
 
+       entry->layout = text_layout_create();
+       text_layout_set_text(entry->layout, entry->text);
+
        widget_set_redraw_handler(entry->widget, text_entry_redraw_handler);
        widget_set_button_handler(entry->widget, text_entry_button_handler);
 
@@ -174,6 +266,7 @@ text_entry_destroy(struct text_entry *entry)
 {
        widget_destroy(entry->widget);
        text_model_destroy(entry->model);
+       text_layout_destroy(entry->layout);
        free(entry->text);
        free(entry);
 }
@@ -286,13 +379,9 @@ text_entry_redraw_handler(struct widget *widget, void 
*data)
        }
 
        cairo_set_source_rgba(cr, 0, 0, 0, 1);
-       cairo_select_font_face(cr, "sans",
-                              CAIRO_FONT_SLANT_NORMAL,
-                              CAIRO_FONT_WEIGHT_BOLD);
-       cairo_set_font_size(cr, 14);
 
        cairo_translate(cr, 10, allocation.height / 2);
-       cairo_show_text(cr, entry->text);
+       text_layout_draw(entry->layout, cr);
        cairo_pop_group_to_source(cr);
        cairo_paint(cr);
 
-- 
1.7.11.4

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