1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
From: "P. J. McDermott" <pj@pehjota.net>
Origin: upstream, https://github.com/SimonSapin/cairocffi/tree/master/utils
Subject: Add missing utils/ directory
--- a/utils/cairocffi_to_pycairo.py
+++ b/utils/cairocffi_to_pycairo.py
@@ -0,0 +1,32 @@
+import ctypes
+import cairo # pycairo
+import cairocffi
+
+pycairo = ctypes.PyDLL(cairo._cairo.__file__)
+pycairo.PycairoContext_FromContext.restype = ctypes.c_void_p
+pycairo.PycairoContext_FromContext.argtypes = 3 * [ctypes.c_void_p]
+ctypes.pythonapi.PyList_Append.argtypes = 2 * [ctypes.c_void_p]
+
+
+def _UNSAFE_cairocffi_context_to_pycairo(cairocffi_context):
+ # Sanity check. Continuing with another type would probably segfault.
+ if not isinstance(cairocffi_context, cairocffi.Context):
+ raise TypeError('Expected a cairocffi.Context, got %r'
+ % cairocffi_context)
+
+ # Create a reference for PycairoContext_FromContext to take ownership of.
+ cairocffi.cairo.cairo_reference(cairocffi_context._pointer)
+ # Casting the pointer to uintptr_t (the integer type as wide as a pointer)
+ # gets the context’s integer address.
+ # On CPython id(cairo.Context) gives the address to the Context type,
+ # as expected by PycairoContext_FromContext.
+ address = pycairo.PycairoContext_FromContext(
+ int(cairocffi.ffi.cast('uintptr_t', cairocffi_context._pointer)),
+ id(cairo.Context),
+ None)
+ assert address
+ # This trick uses Python’s C API
+ # to get a reference to a Python object from its address.
+ temp_list = []
+ assert ctypes.pythonapi.PyList_Append(id(temp_list), address) == 0
+ return temp_list[0]
--- a/utils/cairo_coverage.py
+++ b/utils/cairo_coverage.py
@@ -0,0 +1,23 @@
+import inspect
+import pycparser
+import cairocffi
+
+ALL_THE_CODE = ''.join(
+ line
+ for module in [
+ cairocffi, cairocffi.surfaces, cairocffi.patterns,
+ cairocffi.fonts, cairocffi.context, cairocffi.matrix]
+ for line in inspect.getsourcelines(module)[0])
+
+
+class Visitor(pycparser.c_ast.NodeVisitor):
+ def visit_Decl(self, node):
+ for _, child in node.children():
+ if isinstance(child, pycparser.c_ast.FuncDecl):
+ if ('cairo.' + node.name) not in ALL_THE_CODE and not (
+ node.name.endswith('user_data')):
+ print(node.name)
+ break
+
+print('cairo functions never used in cairocffi:\n')
+Visitor().visit(pycparser.CParser().parse(cairocffi.constants._CAIRO_HEADERS))
--- a/utils/compare_pycairo.py
+++ b/utils/compare_pycairo.py
@@ -0,0 +1,24 @@
+import cairo as pycairo
+import cairocffi
+
+# We want the real pycairo
+assert pycairo is not cairocffi
+
+
+print('Missing pycairo API:\n')
+
+for name in dir(pycairo):
+ pycairo_obj = getattr(pycairo, name)
+ cairocffi_obj = getattr(cairocffi, name, None)
+ if name.startswith(('_', 'version', 'CAPI')):
+ continue
+ if cairocffi_obj is None:
+ print(name)
+ elif isinstance(pycairo_obj, type):
+ for method_name in dir(pycairo_obj):
+ if method_name.startswith('__'):
+ continue
+ pycairo_method = getattr(pycairo_obj, method_name)
+ cairocffi_method = getattr(cairocffi_obj, method_name, None)
+ if cairocffi_method is None:
+ print('%s.%s' % (name, method_name))
--- a/utils/pango_example.py
+++ b/utils/pango_example.py
@@ -0,0 +1,56 @@
+# coding: utf8
+import cairocffi
+import cffi
+
+
+ffi = cffi.FFI()
+ffi.include(cairocffi.ffi)
+ffi.cdef('''
+ /* GLib */
+ typedef void* gpointer;
+ void g_object_unref (gpointer object);
+
+ /* Pango and PangoCairo */
+ typedef ... PangoLayout;
+ typedef enum {
+ PANGO_ALIGN_LEFT,
+ PANGO_ALIGN_CENTER,
+ PANGO_ALIGN_RIGHT
+ } PangoAlignment;
+ int pango_units_from_double (double d);
+ PangoLayout * pango_cairo_create_layout (cairo_t *cr);
+ void pango_cairo_show_layout (cairo_t *cr, PangoLayout *layout);
+ void pango_layout_set_width (PangoLayout *layout, int width);
+ void pango_layout_set_alignment (
+ PangoLayout *layout, PangoAlignment alignment);
+ void pango_layout_set_markup (
+ PangoLayout *layout, const char *text, int length);
+''')
+gobject = ffi.dlopen('gobject-2.0')
+pango = ffi.dlopen('pango-1.0')
+pangocairo = ffi.dlopen('pangocairo-1.0')
+
+gobject_ref = lambda pointer: ffi.gc(pointer, gobject.g_object_unref)
+units_from_double = pango.pango_units_from_double
+
+
+def write_example_pdf(target):
+ pt_per_mm = 72 / 25.4
+ width, height = 210 * pt_per_mm, 297 * pt_per_mm # A4 portrait
+ surface = cairocffi.PDFSurface(target, width, height)
+ context = cairocffi.Context(surface)
+ context.translate(0, 300)
+ context.rotate(-0.2)
+
+ layout = gobject_ref(
+ pangocairo.pango_cairo_create_layout(context._pointer))
+ pango.pango_layout_set_width(layout, units_from_double(width))
+ pango.pango_layout_set_alignment(layout, pango.PANGO_ALIGN_CENTER)
+ markup = u'<span font="italic 30">Hi from Παν語!</span>'
+ markup = ffi.new('char[]', markup.encode('utf8'))
+ pango.pango_layout_set_markup(layout, markup, -1)
+ pangocairo.pango_cairo_show_layout(context._pointer, layout)
+
+
+if __name__ == '__main__':
+ write_example_pdf(target='pango_example.pdf')
--- a/utils/pycairo_to_cairocffi.py
+++ b/utils/pycairo_to_cairocffi.py
@@ -0,0 +1,25 @@
+import cairo # pycairo
+import cairocffi
+
+
+def _UNSAFE_pycairo_context_to_cairocffi(pycairo_context):
+ # Sanity check. Continuing with another type would probably segfault.
+ if not isinstance(pycairo_context, cairo.Context):
+ raise TypeError('Expected a cairo.Context, got %r' % pycairo_context)
+
+ # On CPython, id() gives the memory address of a Python object.
+ # pycairo implements Context as a C struct:
+ # typedef struct {
+ # PyObject_HEAD
+ # cairo_t *ctx;
+ # PyObject *base;
+ # } PycairoContext;
+ # Still on CPython, object.__basicsize__ is the size of PyObject_HEAD,
+ # ie. the offset to the ctx field.
+ # ffi.cast() converts the integer address to a cairo_t** pointer.
+ # [0] dereferences that pointer, ie. read the ctx field.
+ # The result is a cairo_t* pointer that cairocffi can use.
+ return cairocffi.Context._from_pointer(
+ cairocffi.ffi.cast('cairo_t **',
+ id(pycairo_context) + object.__basicsize__)[0],
+ incref=True)
--- a/utils/tests.py
+++ b/utils/tests.py
@@ -0,0 +1,27 @@
+import io
+import cairo # pycairo
+import cairocffi
+
+from pycairo_to_cairocffi import _UNSAFE_pycairo_context_to_cairocffi
+from cairocffi_to_pycairo import _UNSAFE_cairocffi_context_to_pycairo
+import pango_example
+
+
+def test():
+ cairocffi_context = cairocffi.Context(cairocffi.PDFSurface(None, 10, 20))
+ cairocffi_context.scale(2, 3)
+ pycairo_context = _UNSAFE_cairocffi_context_to_pycairo(cairocffi_context)
+ cairocffi_context2 = _UNSAFE_pycairo_context_to_cairocffi(pycairo_context)
+ assert tuple(cairocffi_context.get_matrix()) == (2, 0, 0, 3, 0, 0)
+ assert tuple(cairocffi_context2.get_matrix()) == (2, 0, 0, 3, 0, 0)
+ assert tuple(pycairo_context.get_matrix()) == (2, 0, 0, 3, 0, 0)
+ assert cairocffi_context2._pointer == cairocffi_context._pointer
+
+ file_obj = io.BytesIO()
+ # Mostly test that this runs without raising.
+ pango_example.write_example_pdf(file_obj)
+ assert file_obj.getvalue().startswith(b'%PDF')
+
+
+if __name__ == '__main__':
+ test()
|
