trinary_choice: make labels optional

So one can make a binary choice by leaving the middle one empty.

Author: benma

src/rust/bitbox02-rust/src/hww/api/bip85.rs

@@ -59,7 +59,7 @@ async fn process_bip39() -> Result<(), Error> {
     })
     .await?;
 
-    let num_words: u32 = match choose("How many words?", "12", "18", "24").await {
+    let num_words: u32 = match choose("How many words?", Some("12"), Some("18"), Some("24")).await {
         TrinaryChoice::TRINARY_CHOICE_LEFT => 12,
         TrinaryChoice::TRINARY_CHOICE_MIDDLE => 18,
         TrinaryChoice::TRINARY_CHOICE_RIGHT => 24,

src/rust/bitbox02-rust/src/workflow/mnemonic.rs

@@ -290,7 +290,8 @@ async fn get_12th_18th_word(
 
 /// Retrieve a BIP39 mnemonic sentence of 12, 18 or 24 words from the user.
 pub async fn get() -> Result<zeroize::Zeroizing<String>, CancelError> {
-    let num_words: usize = match choose("How many words?", "12", "18", "24").await {
+    let num_words: usize = match choose("How many words?", Some("12"), Some("18"), Some("24")).await
+    {
         TrinaryChoice::TRINARY_CHOICE_LEFT => 12,
         TrinaryChoice::TRINARY_CHOICE_MIDDLE => 18,
         TrinaryChoice::TRINARY_CHOICE_RIGHT => 24,

src/rust/bitbox02-rust/src/workflow/trinary_choice.rs

@@ -22,9 +22,9 @@ pub use bitbox02::ui::TrinaryChoice;
 
 pub async fn choose(
     message: &str,
-    label_left: &str,
-    label_middle: &str,
-    label_right: &str,
+    label_left: Option<&str>,
+    label_middle: Option<&str>,
+    label_right: Option<&str>,
 ) -> TrinaryChoice {
     let result = RefCell::new(None as Option<TrinaryChoice>);
 

src/rust/bitbox02/src/ui/ui.rs

@@ -318,9 +318,9 @@ pub fn menu_create(params: MenuParams<'_>) -> Component<'_> {
 
 pub fn trinary_choice_create<'a>(
     message: &'a str,
-    label_left: &'a str,
-    label_middle: &'a str,
-    label_right: &'a str,
+    label_left: Option<&'a str>,
+    label_middle: Option<&'a str>,
+    label_right: Option<&'a str>,
     chosen_callback: TrinaryChoiceCb,
 ) -> Component<'a> {
     unsafe extern "C" fn c_chosen_cb(choice: TrinaryChoice, param: *mut c_void) {
@@ -329,12 +329,25 @@ pub fn trinary_choice_create<'a>(
     }
 
     let chosen_cb_param = Box::into_raw(Box::new(chosen_callback)) as *mut c_void;
+    let label_left = label_left.map(|label| crate::util::str_to_cstr_vec(label).unwrap());
+    let label_middle = label_middle.map(|label| crate::util::str_to_cstr_vec(label).unwrap());
+    let label_right = label_right.map(|label| crate::util::str_to_cstr_vec(label).unwrap());
     let component = unsafe {
         bitbox02_sys::trinary_choice_create(
-            crate::util::str_to_cstr_vec(message).unwrap().as_ptr(), // copied in C
-            crate::util::str_to_cstr_vec(label_left).unwrap().as_ptr(), // copied in C
-            crate::util::str_to_cstr_vec(label_middle).unwrap().as_ptr(), // copied in C
-            crate::util::str_to_cstr_vec(label_right).unwrap().as_ptr(), // copied in C
+            // copied in C
+            crate::util::str_to_cstr_vec(message).unwrap().as_ptr(),
+            // copied in C
+            label_left
+                .as_ref()
+                .map_or_else(|| core::ptr::null(), |label| label.as_ptr()),
+            // copied in C
+            label_middle
+                .as_ref()
+                .map_or_else(|| core::ptr::null(), |label| label.as_ptr()),
+            // copied in C
+            label_right
+                .as_ref()
+                .map_or_else(|| core::ptr::null(), |label| label.as_ptr()),
             Some(c_chosen_cb as _),
             chosen_cb_param,
             core::ptr::null_mut(), // parent component, there is no parent.

src/rust/bitbox02/src/ui/ui_stub.rs

@@ -107,9 +107,9 @@ pub fn menu_create(_params: MenuParams<'_>) -> Component<'_> {
 
 pub fn trinary_choice_create<'a>(
     _message: &'a str,
-    _label_left: &'a str,
-    _label_middle: &'a str,
-    _label_right: &'a str,
+    _label_left: Option<&'a str>,
+    _label_middle: Option<&'a str>,
+    _label_right: Option<&'a str>,
     _chosen_callback: TrinaryChoiceCb,
 ) -> Component<'a> {
     panic!("not implemented")

src/rust/bitbox02/src/ui/ui_stub_c_unit_tests.rs

@@ -117,9 +117,9 @@ pub fn menu_create(_params: MenuParams<'_>) -> Component<'_> {
 
 pub fn trinary_choice_create<'a>(
     _message: &'a str,
-    _label_left: &'a str,
-    _label_middle: &'a str,
-    _label_right: &'a str,
+    _label_left: Option<&'a str>,
+    _label_middle: Option<&'a str>,
+    _label_right: Option<&'a str>,
     _chosen_callback: TrinaryChoiceCb,
 ) -> Component<'a> {
     panic!("not implemented")

src/ui/components/trinary_choice.c

@@ -95,24 +95,31 @@ component_t* trinary_choice_create(
         ui_util_add_sub_component(component, label_create(message, NULL, CENTER, component));
     }
 
-    data->button_left = button_create(label_left, bottom_slider, 0, _left_selected, component);
-    ui_util_add_sub_component(component, data->button_left);
-
-    data->button_middle =
-        button_create(label_middle, bottom_slider, 0, _middle_selected, component);
-    ui_util_add_sub_component(component, data->button_middle);
-
-    data->button_right = button_create(label_right, bottom_slider, 0, _right_selected, component);
-    ui_util_add_sub_component(component, data->button_right);
-
-    ui_util_position_left_bottom_offset(component, data->button_left, 0, 0);
-    ui_util_position_left_bottom_offset(
-        component,
-        data->button_middle,
-        SCREEN_WIDTH / 2 - data->button_middle->dimension.width / 2,
-        0);
-    ui_util_position_left_bottom_offset(
-        component, data->button_right, SCREEN_WIDTH - data->button_right->dimension.width, 0);
+    if (label_left != NULL) {
+        data->button_left = button_create(label_left, bottom_slider, 0, _left_selected, component);
+        ui_util_add_sub_component(component, data->button_left);
+        ui_util_position_left_bottom_offset(component, data->button_left, 0, 0);
+    }
+
+    if (label_middle != NULL) {
+        data->button_middle =
+            button_create(label_middle, bottom_slider, 0, _middle_selected, component);
+        ui_util_add_sub_component(component, data->button_middle);
+        ui_util_position_left_bottom_offset(
+            component,
+            data->button_middle,
+            SCREEN_WIDTH / 2 - data->button_middle->dimension.width / 2,
+            0);
+    }
+
+    if (label_right != NULL) {
+        data->button_right =
+            button_create(label_right, bottom_slider, 0, _right_selected, component);
+        ui_util_add_sub_component(component, data->button_right);
+
+        ui_util_position_left_bottom_offset(
+            component, data->button_right, SCREEN_WIDTH - data->button_right->dimension.width, 0);
+    }
 
     return component;
 }