First pass at fixing issue 99

A lot of code touched because low level functions needed to pass up
error messages reliably, and this had to propagate up the entire
driver hierarchy.

Tested OK *in English* on:
     > Linux
     > OSX 10.10.x
     > Windows VS2017
     > Windows mingw64
I have no way to test on Android, but it might work.

TODO: Needs testing in other languages to verify proper UTF8 error messages,
      esp. with Windows VS, due to complexities with FormatMessage() -- see get_ms_errmsg()

1 files changed, 23 insertions, 6 deletions

diff --git a/src/Fl_File_Chooser.fl b/src/Fl_File_Chooser.fl
index d222bd1c8..7cf01e1c7 100644
--- a/src/Fl_File_Chooser.fl
+++ b/src/Fl_File_Chooser.fl
@@ -66,7 +66,8 @@ class FL_EXPORT Fl_File_Chooser {open
   }
   decl {void update_preview();} {private local
   }
-  Function {Fl_File_Chooser(const char *d, const char *p, int t, const char *title)} {} {
+  Function {Fl_File_Chooser(const char *d, const char *p, int t, const char *title)} {open
+  } {
     code {if (!prefs_) {
   prefs_ = new Fl_Preferences(Fl_Preferences::CORE_USER, "fltk.org", "filechooser");
 }} {}
@@ -77,11 +78,11 @@ class FL_EXPORT Fl_File_Chooser {open
 fileList->deselect();
 Fl::remove_timeout((Fl_Timeout_Handler)previewCB, this);
 window->hide();} open
-      private xywh {507 327 490 380} type Double hide resizable
+      private xywh {1171 438 490 380} type Double resizable
       code0 {if (title) window->label(title);}
       code1 {\#include <stdio.h>}
       code2 {\#include <stdlib.h>}
-      code3 {\#include <string.h>} modal
+      code3 {\#include <string.h>} modal visible
     } {
       Fl_Group {} {open
         private xywh {10 10 470 25}
@@ -106,14 +107,18 @@ window->hide();} open
         }
       }
       Fl_Tile {} {
-        callback {update_preview();}
+        callback {update_preview();} open
         private xywh {10 45 470 225} resizable
       } {
         Fl_File_Browser fileList {
           callback {fileListCB();}
-          private xywh {10 45 295 225} type Hold hotspot
+          private xywh {10 45 295 225} type Hold box DOWN_BOX hotspot
           code0 {\#include <FL/Fl_File_Browser.H>}
         }
+        Fl_Box errorBox {
+          label {dynamic error display} selected
+          private xywh {10 45 295 225} box DOWN_BOX color 7 labelsize 18 labelcolor 1 align 149 hide
+        }
         Fl_Box previewBox {
           label {?}
           private xywh {305 45 175 225} box DOWN_BOX labelsize 100 align 80
@@ -349,7 +354,7 @@ okButton->parent()->init_sizes();} {}
   } {
     code {fileList->textfont(f);} {}
   }
-  Function {textfont()} {selected return_type Fl_Font
+  Function {textfont()} {return_type Fl_Font
   } {
     code {return (fileList->textfont());} {}
   }
@@ -475,6 +480,18 @@ window->resizable(svres);} {}
     }
     code {return ret;} {}
   }
+  Function {show_error_box(int val)} {
+    comment {Show error box if val=1, hide if val=0} open protected return_type void
+  } {
+    code {if ( val ) {
+  errorBox->color(fileList->color()); // inherit fileList's bg color
+  errorBox->show();
+  fileList->hide();
+} else {
+  errorBox->hide();
+  fileList->show();
+}} {}
+  }
 }
 
 decl {FL_EXPORT char *fl_dir_chooser(const char *message,const char *fname,int relative=0);} {public local