working on some tests. this commit is broken

imgui-examples/examples/keyboard.rs

@@ -76,11 +76,23 @@ fn main() {
                     ctrl_a_counter
                 ));
 
+                struct Cback;
+                impl TextCallbackHandler for Cback {
+                    fn char_filter(&mut self, c: char, txt: &TextInformation<'_>) -> Option<char> {
+                        if c == 'a' {
+                            None
+                        } else {
+                            Some(c)
+                        }
+                    }
+                }
+
                 // Note that `is_key_released` gives the state of the
                 // key regardless of what widget has focus, for
                 // example, if you try to type into this input, the
                 // above interaction still counts the key presses.
                 ui.input_text(im_str!("##Dummy text input widget"), &mut text_buffer)
+                    .callback(InputTextCallback::CHAR_FILTER, &mut Cback)
                     .hint(im_str!("Example text input"))
                     .build();
 

imgui/src/input_widget.rs

@@ -116,14 +116,14 @@ struct CallbackData<'a> {
     user_data: &'a mut UserData<'a>,
 }
 
-pub struct TextCallbackData<'a> {
-    pub event_flag: InputTextFlags,
-    pub flags: InputTextFlags,
-    pub user_data: UserData<'a>,
-    pub event_char: char,
-    pub event_key: EventDirection,
-    pub buf: TextCallbackBuffer<'a>,
-}
+// pub struct TextCallbackData<'a> {
+//     pub event_flag: InputTextFlags,
+//     pub flags: InputTextFlags,
+//     pub user_data: UserData<'a>,
+//     pub event_char: char,
+//     pub event_key: EventDirection,
+//     pub buf: TextCallbackBuffer<'a>,
+// }
 
 pub struct TextCallbackBuffer<'a> {
     buf: &'a mut str,
@@ -295,10 +295,10 @@ extern "C" fn callback(data: *mut sys::ImGuiInputTextCallbackData) -> c_int {
         let text_info = TextInformation {
             flags: InputTextFlags::from_bits((*data).Flags as u32).unwrap(),
             buf: TextCallbackBuffer {
-                buf: std::str::from_utf8_mut(std::slice::from_raw_parts_mut(
+                buf: std::str::from_utf8_mut(dbg!(std::slice::from_raw_parts_mut(
                     (*data).Buf as *mut u8,
-                    (*data).BufSize as usize - 1,
-                ))
+                    (*data).BufSize as usize,
+                )))
                 .expect("internal imgui error -- it boofed a utf8"),
                 dirty: &mut (*data).BufDirty,
                 cursor_pos: &mut (*data).CursorPos,

imgui/src/lib.rs

@@ -20,8 +20,9 @@ pub use self::fonts::glyph_ranges::*;
 pub use self::input::keyboard::*;
 pub use self::input::mouse::*;
 pub use self::input_widget::{
-    InputFloat, InputFloat2, InputFloat3, InputFloat4, InputInt, InputInt2, InputInt3, InputInt4,
-    InputText, InputTextFlags, InputTextMultiline,
+    EventDirection, InputFloat, InputFloat2, InputFloat3, InputFloat4, InputInt, InputInt2,
+    InputInt3, InputInt4, InputText, InputTextCallback, InputTextMultiline, TextCallbackBuffer,
+    TextCallbackHandler, TextInformation, InputTextFlags
 };
 pub use self::io::*;
 pub use self::layout::*;