STR #2873: new function Fl_Image::fail() that returns 0, ERR_NO_IMAGE, ERR_FORMAT, or ERR_FILE_ACCESS to make life easier when loading images.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10732 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 17 insertions, 5 deletions

diff --git a/src/Fl_PNM_Image.cxx b/src/Fl_PNM_Image.cxx
index c4a65076f..40073b26a 100644
--- a/src/Fl_PNM_Image.cxx
+++ b/src/Fl_PNM_Image.cxx
@@ -37,11 +37,18 @@
 // 'Fl_PNM_Image::Fl_PNM_Image()' - Load a PNM image...
 //
 
-/** 
-  The constructor loads the named PNM image. 
-  <P>The inherited destructor free all memory and server resources that are used by the image.
-*/
 
+/** 
+ The constructor loads the named PNM image.
+  
+ The inherited destructor free all memory and server resources that are used by 
+ the image.
+ 
+ Use Fl_Image::fail() to check if Fl_BMP_Image failed to load. fail() returns
+ ERR_FILE_ACCESS if the file could not bo opened or read, ERR_FORMAT if the
+ PNM format could not be decoded, and ERR_NO_IMAGE if the image could not
+ be loaded for another reason.
+ */
 Fl_PNM_Image::Fl_PNM_Image(const char *name)	// I - File to read
   : Fl_RGB_Image(0,0,0) {
   FILE		*fp;		// File pointer
@@ -56,7 +63,10 @@ Fl_PNM_Image::Fl_PNM_Image(const char *name)	// I - File to read
 		maxval;		// Maximum pixel value
 
 
-  if ((fp = fl_fopen(name, "rb")) == NULL) return;
+  if ((fp = fl_fopen(name, "rb")) == NULL) {
+    ld(ERR_FILE_ACCESS);
+    return;
+  }
 
   //
   // Read the file header in the format:
@@ -75,6 +85,7 @@ Fl_PNM_Image::Fl_PNM_Image(const char *name)	// I - File to read
   if (!lineptr) {
     fclose(fp);
     Fl::error("Early end-of-file in PNM file \"%s\"!", name);
+    ld(ERR_FILE_ACCESS);
     return;
   }
 
@@ -122,6 +133,7 @@ Fl_PNM_Image::Fl_PNM_Image(const char *name)	// I - File to read
   if (((size_t)w()) * h() * d() > max_size() ) {
     Fl::warning("PNM file \"%s\" is too large!\n", name);
     fclose(fp);
+    w(0); h(0); d(0); ld(ERR_FORMAT);
     return;
   }
   array       = new uchar[w() * h() * d()];