more cplusplus hackery

cplusplus/VImage.cc

@@ -37,10 +37,11 @@
 #include <cstdio>
 
 #include <vips/vips.h>
-#include <vips/internal.h>
 #include <vips/debug.h>
 
-#include <vips/vipscpp.h>
+#include <gobject/gvaluecollector.h>
+
+#include "include/vips/vips8"
 
 #ifdef WITH_DMALLOC
 #include <dmalloc.h>
@@ -54,7 +55,9 @@ VIPS_NAMESPACE_START
 
 /* Useful to have these as namespaced C++ functions.
  */
-void init( const char *argv0 )
+void 
+init( const char *argv0 )
+	throw( VError )
 {
 	if( vips_init( argv0 ) )
 		throw VError();
@@ -70,14 +73,139 @@ void thread_shutdown()
 	vips_thread_shutdown(); 
 }
 
+static void
+call_get( GParamSpec *pspec, void *arg )
+{
+	/* We've read out of the VipsObject to the pointer. If it's a
+	 * VipsImage, we need to box it.
+	 */
+	if( G_IS_PARAM_SPEC_OBJECT( pspec ) ) {
+		VImage *image = new VImage( *((VipsImage **) arg) ); 
 
+		*((VImage *) arg) = *image; 
+	}
+}
 
+static void
+call_set( GParamSpec *pspec, GValue *value )
+{
+	if( G_VALUE_HOLDS( value, VIPS_TYPE_IMAGE ) ) {
+		/* A VImage has been written to the GValue, extract the VImage
+		 * and swap it for the underlying VipsImage* pointer.
+		 */
+		VImage *image = static_cast<VImage *>( 
+			g_value_peek_pointer( value ) );
 
+		g_value_set_object( value, (gpointer) (image->image()) ); 
+	}
+}
 
+/* Some systems do not have va_copy() ... this might work (it does on MSVC,
+ * apparently).
+ *
+ * FIXME ... this should be in configure.in
+ */
+#ifndef va_copy
+#define va_copy(d,s) ((d) = (s))
+#endif
+
+void
+call( const char *operation_name, ... )
+	throw( VError )
+{
+	VipsCollect collect;
+	VipsOperation *operation;
+	int result;
+	va_list required;
+	va_list optional;
+
+	if( !(operation = vips_operation_new( operation_name )) )
+		throw VError(); 
+
+	/* We have to break the va_list into separate required and optional 
+	 * components.
+	 *
+	 * Note the start, grab the required, then copy and reuse.
+	 */
+	va_start( required, operation_name );
+
+	va_copy( optional, required );
+
+	VIPS_ARGUMENT_FOR_ALL( operation, 
+		pspec, argument_class, argument_instance ) {
+
+		g_assert( argument_instance );
+
+		if( (argument_class->flags & VIPS_ARGUMENT_REQUIRED) ) {
+			VIPS_ARGUMENT_COLLECT_SET( pspec, argument_class, 
+				optional );
+
+			VIPS_ARGUMENT_COLLECT_GET( pspec, argument_class, 
+				optional );
+
+			VIPS_ARGUMENT_COLLECT_END
+		}
+	} VIPS_ARGUMENT_FOR_ALL_END
+
+	collect.get = call_get;
+	collect.set = call_set;
+	result = vips_call_required_optional( &operation, 
+		&collect, required, optional );
+
+	va_end( required );
+	va_end( optional );
+
+	/* Build failed: junk args.
+	 */
+	if( result ) 
+		vips_object_unref_outputs( VIPS_OBJECT( operation ) );
+
+	/* The operation we have built should now have been reffed by one of 
+	 * its arguments or have finished its work. Either way, we can unref.
+	 */
+	g_object_unref( operation );
+
+	if( result )
+		throw VError(); 
+}
+
+int
+call_split( const char *operation_name, va_list optional, ... ) 
+{
+	VipsOperation *operation;
+	va_list required;
+	VipsCollect collect;
+	int result;
+
+	if( !(operation = vips_operation_new( operation_name )) )
+		throw VError(); 
+
+	va_start( required, optional );
+
+	collect.get = call_get;
+	collect.set = call_set;
+	result = vips_call_required_optional( &operation, 
+		&collect, required, optional );
+
+	va_end( required );
+
+	/* Build failed: junk args.
+	 */
+	if( result ) 
+		vips_object_unref_outputs( VIPS_OBJECT( operation ) );
+
+	/* The operation we have built should now have been reffed by one of 
+	 * its arguments or have finished its work. Either way, we can unref.
+	 */
+	g_object_unref( operation );
+
+	if( result )
+		throw VError(); 
+}
 
 // see vips_image_new_from_file()
 VImage::VImage( const char *name, ... ) 
-	__attribute__((sentinel)) throw( VError )
+	throw( VError ) 
 {
 	char filename[VIPS_PATH_MAX];
 	char option_string[VIPS_PATH_MAX];
@@ -85,8 +213,6 @@ VImage::VImage( const char *name, ... )
 	va_list ap;
 	int result;
 
-	vips_check_init();
-
 	vips__filename_split8( name, filename, option_string );
 	if( !(operation_name = vips_foreign_find_load( filename )) )
 		throw VError(); 
@@ -102,14 +228,13 @@ VImage::VImage( const char *name, ... )
 
 // see vips_image_new_from_buffer()
 VImage::VImage( void *buffer, size_t length, const char *option_string, ... )
+	throw( VError )
 {
 	const char *operation_name;
 	VipsBlob *blob;
 	va_list ap;
 	int result;
 
-	vips_check_init();
-
 	if( !(operation_name = 
 		vips_foreign_find_load_buffer( buffer, length )) )
 		throw VError();
@@ -130,7 +255,7 @@ VImage::VImage( void *buffer, size_t length, const char *option_string, ... )
 }
 
 // see vips_image_write_to_file()
-void VImage::write( const char *name, ... ) 
+void VImage::write_to_file( const char *name, ... ) 
 	throw( VError )
 {
 	char filename[VIPS_PATH_MAX];
@@ -145,7 +270,7 @@ void VImage::write( const char *name, ... )
 
 	va_start( ap, name );
 	result = vips_call_split_option_string( operation_name, option_string,
-		ap, this.im, filename );
+		ap, this->im, filename );
 	va_end( ap );
 
 	if( result )
@@ -153,7 +278,7 @@ void VImage::write( const char *name, ... )
 }
 
 // see vips_image_write_to_buffer()
-void *VImage::write( const char *suffix, size_t *size, ... )
+void *VImage::write_to_buffer( const char *suffix, size_t *size, ... )
 	throw( VError )
 {
 	char filename[VIPS_PATH_MAX];
@@ -170,7 +295,7 @@ void *VImage::write( const char *suffix, size_t *size, ... )
 
 	va_start( ap, size );
 	result = vips_call_split_option_string( operation_name, option_string,
-		ap, this.im, &blob );
+		ap, this->im, &blob );
 	va_end( ap );
 
 	if( result )
@@ -194,3 +319,16 @@ void *VImage::write( const char *suffix, size_t *size, ... )
 #include "vips-operators.cc"
 
 VIPS_NAMESPACE_END
+
+
+int
+main( int argc, char **argv )
+{
+	vips8::init( argv[0] ); 
+
+	vips8::VImage x( "/home/john/pics/k2.jpg", NULL );
+
+	printf( "width = %d\n", x.width() ); 
+
+	return( 0 ); 
+}

cplusplus/include/vips/VImage.h

@@ -79,26 +79,22 @@ public:
 	VImage( const char *filename, const char *mode = "r" ) 
 		throw( VError )
 	{
-		vips_check_init();
-
 		if( !(im = vips_image_new_mode( filename, mode )) )
 			throw VError();
 	}
 
 	// see vips_image_new_from_file()
 	VImage( const char *name, ... ) 
-		__attribute__((sentinel)) throw( VError );
+		throw( VError ) __attribute__((sentinel));
 
 	// see vips_image_new_from_buffer()
 	VImage( void *buffer, size_t length, const char *option_string, ... )
-		__attribute__((sentinel)) throw( VError );
+		throw( VError ) __attribute__((sentinel));
 
 	// see vips_image_new_from_memory()
 	VImage( void *data, size_t size, int width, int height, 
 		int bands, VipsBandFormat format ) throw( VError )
 	{
-		vips_check_init();
-
 		if( !(im = vips_image_new_from_memory( data, size, 
 			width, height, bands, format )) )
 			throw VError();
@@ -154,15 +150,15 @@ public:
 			throw VError(); 
 	}
 
-	void write( const char *name, ... ) 
+	void write_to_file( const char *name, ... ) 
-		throw( VError );
+		throw( VError )
 	{
-		if( vips_image_write_to_file( im, out.im ) )
+		if( vips_image_write_to_file( im, name, NULL ) )
 			throw VError(); 
 	}
 
 	// see vips_image_write_to_buffer()
-	void *write( const char *suffix, size_t *size, ... )
+	void *write_to_buffer( const char *suffix, size_t *size, ... )
 		throw( VError );
 
 	// also need

cplusplus/include/vips/vips-operators.h

@@ -1,3 +1,3 @@
 
 VImage add( VImage add_in2, ... ) 
-	__attribute__((sentinel)) throw( VError );
+	throw( VError ) __attribute__((sentinel));

cplusplus/include/vips/vips8

@@ -37,7 +37,7 @@
 #define VIPS_NAMESPACE_START namespace vips8 {
 #define VIPS_NAMESPACE_END }
 
-#include <vips/VError.h>
+#include "VError.h"
-#include <vips/VImage.h>
+#include "VImage.h"
 
 #endif /*VIPS_CPLUSPLUS*/

cplusplus/vips-operators.cc

@@ -1,11 +1,11 @@
-VImage VImage::add( VImage in2 )
+VImage VImage::add( VImage in2, ... )
 	throw( VError )
 {
 	va_list ap;
 	VImage out; 
 	int result;
 
-	va_start( ap, out );
+	va_start( ap, in2 );
 	result = call_split( "add", ap, this, in2, &out );
 	va_end( ap );
 

libvips/include/vips/basic.h

@@ -59,6 +59,25 @@ typedef void *(*VipsSListMap4Fn)( void *item,
 typedef void *(*VipsSListFold2Fn)( void *item, 
 	void *a, void *b, void *c );
 
+/* The value has been read from the VipsOperation and written to the 
+ * arg pointer. @arg is eg. gboolean* for a bool value.
+ */
+typedef void (*VipsCollectGet)( GParamSpec *pspec, void *arg );
+
+/* The value has been read from argv into a GValue. Do any
+ * boxing/unboxing before the GValue is used to set the property.
+ */
+typedef void (*VipsCollectSet)( GParamSpec *pspec, GValue *value );
+
+/* We need to be able to use different things to collect values for the C++
+ * API: we have to box and unbox VipsImage. Set/get need to be parameters.
+ */
+typedef struct _VipsCollect {
+	VipsCollectGet get; 
+	VipsCollectSet set; 
+
+} VipsCollect; 
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/

libvips/include/vips/object.h

@@ -601,7 +601,8 @@ typedef void *(*VipsObjectSetArguments)( VipsObject *object, void *a, void *b );
 VipsObject *vips_object_new( GType type, 
 	VipsObjectSetArguments set, void *a, void *b );
 
-int vips_object_set_valist( VipsObject *object, va_list ap );
+int vips_object_set_valist( VipsObject *object, 
+	VipsCollect *collect, va_list ap );
 int vips_object_set( VipsObject *object, ... )
 	__attribute__((sentinel));
 int vips_object_set_from_string( VipsObject *object, const char *string );

libvips/include/vips/operation.h

@@ -35,8 +35,6 @@
 extern "C" {
 #endif /*__cplusplus*/
 
-#include <vips/vips.h>
-
 typedef enum /*< flags >*/ {
 	VIPS_OPERATION_NONE = 0,
 	VIPS_OPERATION_SEQUENTIAL = 1,
@@ -74,20 +72,6 @@ typedef struct _VipsOperation {
 	 */
 	int pixels;
 
-	/* Get and set functions, used by eg. the C++ interface to box and
-	 * unbox VImage.
-	 */
-
-	/* The value has been read from the VipsOperation and written to the arg
-	 * pointer. @arg is eg. gboolean* for a bool value.
-	 */
-	void (*collect_get)( GParamSpec *pspec, void *arg ); 
-
-	/* The value has been read from argv into a GValue. Do any
-	 * boxing/unboxing before the GValue is used to set the property.
-	 */
-	void (*collect_set)( GParamSpec *pspec, GValue *value );
-
 } VipsOperation;
 
 typedef struct _VipsOperationClass {
@@ -116,6 +100,8 @@ void vips_operation_invalidate( VipsOperation *operation );
 
 int vips_operation_call_valist( VipsOperation *operation, va_list ap );
 VipsOperation *vips_operation_new( const char *name ); 
+int vips_call_required_optional( VipsOperation **operation,
+	VipsCollect *collect, va_list required, va_list optional );
 int vips_call( const char *operation_name, ... )
 	__attribute__((sentinel));
 int vips_call_split( const char *operation_name, va_list optional, ... );

libvips/iofuncs/object.c

@@ -2155,6 +2155,7 @@ vips_object_new( GType type, VipsObjectSetArguments set, void *a, void *b )
 /**
  * vips_object_set_valist:
  * @object: object to set arguments on
+ * @collect: how to box or unbox values
  * @ap: %NULL-terminated list of argument/value pairs
  *
  * See vips_object_set().
@@ -2162,7 +2163,7 @@ vips_object_new( GType type, VipsObjectSetArguments set, void *a, void *b )
  * Returns: 0 on success, -1 on error
  */
 int
-vips_object_set_valist( VipsObject *object, va_list ap )
+vips_object_set_valist( VipsObject *object, VipsCollect *collect, va_list ap )
 {
 	char *name;
 
@@ -2181,6 +2182,9 @@ vips_object_set_valist( VipsObject *object, va_list ap )
 
 		VIPS_ARGUMENT_COLLECT_SET( pspec, argument_class, ap );
 
+		if( collect )
+			collect->set( pspec, &value ); 
+
 		g_object_set_property( G_OBJECT( object ), 
 			name, &value );
 
@@ -2220,7 +2224,7 @@ vips_object_set( VipsObject *object, ... )
 	int result;
 
 	va_start( ap, object );
-	result = vips_object_set_valist( object, ap );
+	result = vips_object_set_valist( object, NULL, ap );
 	va_end( ap );
 
 	return( result );

libvips/iofuncs/operation.c

@@ -181,6 +181,13 @@
  * compatibility only and should be hidden from users.
  */
 
+/**
+ * VipsCollect:
+ *
+ * We need to be able to use different things to collect values for the C++
+ * API: we have to box and unbox VipsImage. Set/get need to be parameters.
+ */
+
 /* Abstract base class for operations.
  */
 
@@ -567,8 +574,8 @@ vips_operation_new( const char *name )
 	return( operation );
 }
 
-/* Some systems do not have va_copy() ... this might work (it does on MSVC),
+/* Some systems do not have va_copy() ... this might work (it does on MSVC,
- * apparently.
+ * apparently).
  *
  * FIXME ... this should be in configure.in
  */
@@ -577,7 +584,8 @@ vips_operation_new( const char *name )
 #endif
 
 static int
-vips_operation_set_valist_required( VipsOperation *operation, va_list ap )
+vips_operation_set_valist_required( VipsOperation *operation, 
+	VipsCollect *collect, va_list ap )
 {
 	VIPS_DEBUG_MSG( "vips_operation_set_valist_required:\n" );
 
@@ -603,8 +611,8 @@ vips_operation_set_valist_required( VipsOperation *operation, va_list ap )
 			}
 #endif /*VIPS_DEBUG */
 
-			if( operation->collect_set )
+			if( collect )
-				operation->collect_set( pspec, &value ); 
+				collect->set( pspec, &value ); 
 
 			g_object_set_property( G_OBJECT( operation ),
 				g_param_spec_get_name( pspec ), &value );
@@ -624,7 +632,8 @@ vips_operation_set_valist_required( VipsOperation *operation, va_list ap )
 }
 
 static int
-vips_operation_get_valist_required( VipsOperation *operation, va_list ap )
+vips_operation_get_valist_required( VipsOperation *operation, 
+	VipsCollect *collect, va_list ap )
 {
 	VIPS_DEBUG_MSG( "vips_operation_get_valist_required:\n" );
 
@@ -672,8 +681,8 @@ vips_operation_get_valist_required( VipsOperation *operation, va_list ap )
 
 			/* Do any boxing/unboxing.
 			 */
-			if( operation->collect_get )
+			if( collect )
-				operation->collect_get( pspec, arg );
+				collect->get( pspec, arg );
 
 			VIPS_ARGUMENT_COLLECT_END
 		}
@@ -683,7 +692,8 @@ vips_operation_get_valist_required( VipsOperation *operation, va_list ap )
 }
 
 static int
-vips_operation_get_valist_optional( VipsOperation *operation, va_list ap )
+vips_operation_get_valist_optional( VipsOperation *operation, 
+	VipsCollect *collect, va_list ap )
 {
 	char *name;
 
@@ -736,8 +746,8 @@ vips_operation_get_valist_optional( VipsOperation *operation, va_list ap )
 
 			/* Do any boxing/unboxing.
 			 */
-			if( operation->collect_get )
+			if( collect )
-				operation->collect_get( pspec, arg );
+				collect->get( pspec, arg );
 		}
 
 		VIPS_ARGUMENT_COLLECT_END
@@ -746,11 +756,25 @@ vips_operation_get_valist_optional( VipsOperation *operation, va_list ap )
 	return( 0 );
 }
 
-/* This can change operation to point at an old, cached one.
+/**
+ * vips_call_required_optional:
+ * @operation: the operation to execute
+ * @collect: how to box and unbox arguments
+ * @required: %va_list of required arguments
+ * @optional: NULL-terminated %va_list of name / value pairs 
+ *
+ * This is the main entry point for the C and C++ varargs APIs. @operation 
+ * is executed, supplying @required and @optional arguments. @collect is used
+ * to do any boxing or unboxing. It can be %NULL for no boxing on unboxing
+ * required (the C case). 
+ *
+ * Beware, this can change @operation to point at an old, cached one.
+ *
+ * Returns: 0 on success, -1 on error
  */
-static int
+int
 vips_call_required_optional( VipsOperation **operation,
-	va_list required, va_list optional ) 
+	VipsCollect *collect, va_list required, va_list optional ) 
 {
 	int result;
 	va_list a;
@@ -762,8 +786,8 @@ vips_call_required_optional( VipsOperation **operation,
 	 */
 	va_copy( a, required );
 	va_copy( b, optional );
-	result = vips_operation_set_valist_required( *operation, a ) ||
+	result = vips_operation_set_valist_required( *operation, collect, a ) ||
-		vips_object_set_valist( VIPS_OBJECT( *operation ), b );
+		vips_object_set_valist( VIPS_OBJECT( *operation ), collect, b );
 	va_end( a );
 	va_end( b );
 
@@ -779,8 +803,10 @@ vips_call_required_optional( VipsOperation **operation,
 	 */
 	va_copy( a, required );
 	va_copy( b, optional );
-	result = vips_operation_get_valist_required( *operation, required ) ||
+	result = vips_operation_get_valist_required( *operation, 
-		vips_operation_get_valist_optional( *operation, optional );
+			collect, required ) ||
+		vips_operation_get_valist_optional( *operation, 
+			collect, optional );
 	va_end( a );
 	va_end( b );
 
@@ -801,7 +827,7 @@ vips_call_by_name( const char *operation_name,
 		return( -1 );
 
 	/* Set str options before vargs options, so the user can't override
-	 * thnigs we set deliberately.
+	 * things we set deliberately.
 	 */
 	if( option_string &&
 		vips_object_set_from_string( VIPS_OBJECT( operation ), 
@@ -812,7 +838,8 @@ vips_call_by_name( const char *operation_name,
 		return( -1 ); 
 	}
 
-	result = vips_call_required_optional( &operation, required, optional );
+	result = vips_call_required_optional( &operation, 
+		NULL, required, optional );
 
 	/* Build failed: junk args and back out.
 	 */