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Cairo: A Vector Graphics Library | |
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enum cairo_status_t; const char* cairo_status_to_string (cairo_status_t status); void cairo_debug_reset_static_data (void);
Cairo uses a single status type to represent all kinds of errors. A status
value of CAIRO_STATUS_SUCCESS represents no error and has an integer value
of zero. All other status values represent an error.
Cairo's error handling is designed to be easy to use and safe. All major
cairo objects retain an error status internally which
can be queried anytime by the users using cairo*_status() calls. In
the mean time, it is safe to call all cairo functions normally even if the
underlying object is in an error status. This means that no error handling
code is required before or after each individual cairo function call.
typedef enum _cairo_status {
CAIRO_STATUS_SUCCESS = 0,
CAIRO_STATUS_NO_MEMORY,
CAIRO_STATUS_INVALID_RESTORE,
CAIRO_STATUS_INVALID_POP_GROUP,
CAIRO_STATUS_NO_CURRENT_POINT,
CAIRO_STATUS_INVALID_MATRIX,
CAIRO_STATUS_INVALID_STATUS,
CAIRO_STATUS_NULL_POINTER,
CAIRO_STATUS_INVALID_STRING,
CAIRO_STATUS_INVALID_PATH_DATA,
CAIRO_STATUS_READ_ERROR,
CAIRO_STATUS_WRITE_ERROR,
CAIRO_STATUS_SURFACE_FINISHED,
CAIRO_STATUS_SURFACE_TYPE_MISMATCH,
CAIRO_STATUS_PATTERN_TYPE_MISMATCH,
CAIRO_STATUS_INVALID_CONTENT,
CAIRO_STATUS_INVALID_FORMAT,
CAIRO_STATUS_INVALID_VISUAL,
CAIRO_STATUS_FILE_NOT_FOUND,
CAIRO_STATUS_INVALID_DASH,
CAIRO_STATUS_INVALID_DSC_COMMENT,
CAIRO_STATUS_INVALID_INDEX,
CAIRO_STATUS_CLIP_NOT_REPRESENTABLE,
CAIRO_STATUS_TEMP_FILE_ERROR,
CAIRO_STATUS_INVALID_STRIDE
/* after adding a new error: update CAIRO_STATUS_LAST_STATUS in cairoint.h */
} cairo_status_t;
cairo_status_t is used to indicate errors that can occur when
using Cairo. In some cases it is returned directly by functions.
but when using cairo_t, the last error, if any, is stored in
the context and can be retrieved with cairo_status().
New entries may be added in future versions. Use cairo_status_to_string()
to get a human-readable representation of an error message.
| no error has occurred | |
| out of memory | |
cairo_restore() called without matching cairo_save()
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| no saved group to pop | |
| no current point defined | |
| invalid matrix (not invertible) | |
| invalid value for an input cairo_status_t | |
NULL pointer
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| input string not valid UTF-8 | |
| input path data not valid | |
| error while reading from input stream | |
| error while writing to output stream | |
| target surface has been finished | |
| the surface type is not appropriate for the operation | |
| the pattern type is not appropriate for the operation | |
| invalid value for an input cairo_content_t | |
| invalid value for an input cairo_format_t | |
| invalid value for an input Visual* | |
| file not found | |
| invalid value for a dash setting | |
| invalid value for a DSC comment (Since 1.2) | |
| invalid index passed to getter (Since 1.4) | |
| clip region not representable in desired format (Since 1.4) | |
| error creating or writing to a temporary file (Since 1.6) | |
| invalid value for stride (Since 1.6) |
const char* cairo_status_to_string (cairo_status_t status);
Provides a human-readable description of a cairo_status_t.
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a cairo status |
Returns : |
a string representation of the status |
void cairo_debug_reset_static_data (void);
Resets all static data within cairo to its original state, (ie. identical to the state at the time of program invocation). For example, all caches within cairo will be flushed empty.
This function is intended to be useful when using memory-checking
tools such as valgrind. When valgrind's memcheck analyzes a
cairo-using program without a call to cairo_debug_reset_static_data(),
it will report all data reachable via cairo's static objects as
"still reachable". Calling cairo_debug_reset_static_data() just prior
to program termination will make it easier to get squeaky clean
reports from valgrind.
WARNING: It is only safe to call this function when there are no active cairo objects remaining, (ie. the appropriate destroy functions have been called as necessary). If there are active cairo objects, this call is likely to cause a crash, (eg. an assertion failure due to a hash table being destroyed when non-empty).