From 438632c7853ff6a3e2882e9c98d3b3f1ce9e0f0b Mon Sep 17 00:00:00 2001
From: Lukas Bielesch <bielesch.lukas@gmail.com>
Date: Wed, 19 Mar 2025 10:18:20 +0100
Subject: [PATCH] fix(eckhart): fix last pending char for max len passphrase

---
 .../firmware/keyboard/keypad.rs               | 36 ++++++++++++++++---
 .../firmware/keyboard/passphrase.rs           | 31 ++++++++++++----
 .../layout_eckhart/firmware/keyboard/pin.rs   |  4 +++
 3 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/keypad.rs b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/keypad.rs
index 0656e255b3..ac51dfdf98 100644
--- a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/keypad.rs
+++ b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/keypad.rs
@@ -34,12 +34,20 @@ pub enum ButtonState {
 const KEYPAD_MAX_KEYS: usize = 10;
 type KeypadKeys = [Maybe<Button>; KEYPAD_MAX_KEYS];
 
+/// Represents the state of a keypad, including individual button states.
 pub struct KeypadState {
+    /// State of the "Back" button.
     pub back: ButtonState,
+    /// State of the "Erase" button.
     pub erase: ButtonState,
+    /// State of the "Cancel" button.
     pub cancel: ButtonState,
+    /// State of the "Confirm" button.
     pub confirm: ButtonState,
+    /// Common state of the keypad generic keys.
     pub keys: ButtonState,
+    /// Optional override for one key, containing the index and state.
+    pub override_key: Option<(usize, ButtonState)>,
 }
 
 pub struct Keypad {
@@ -167,7 +175,7 @@ impl Keypad {
         Self::apply_button_state(&mut self.erase, &state.erase, ctx);
         Self::apply_button_state(&mut self.cancel, &state.cancel, ctx);
         Self::apply_button_state(&mut self.confirm, &state.confirm, ctx);
-        self.set_keys_state(ctx, &state.keys);
+        self.set_keys_state(ctx, &state.keys, state.override_key);
     }
 
     /// Set the content of a key at the specified index.
@@ -221,11 +229,31 @@ impl Keypad {
         }
     }
 
-    /// Set the state of all key buttons
-    pub fn set_keys_state(&mut self, ctx: &mut EventCtx, state: &ButtonState) {
-        for btn in self.keys.iter_mut() {
+    /// Sets the state of all key buttons, except for an optional override key.
+    pub fn set_keys_state(
+        &mut self,
+        ctx: &mut EventCtx,
+        state: &ButtonState,
+        override_key: Option<(usize, ButtonState)>,
+    ) {
+        // Apply the state to all keys except the override key.
+        for (idx, btn) in self.keys.iter_mut().enumerate() {
+            if let Some((override_idx, _)) = override_key {
+                if override_idx == idx {
+                    continue; // Skip setting the state for the override key
+                }
+            }
             Self::apply_button_state(btn, state, ctx);
         }
+
+        // Apply the override state if any.
+        if let Some((override_idx, override_state)) = override_key {
+            Self::apply_button_state(
+                self.get_button_mut(&KeypadButton::Key(override_idx)),
+                &override_state,
+                ctx,
+            );
+        }
     }
 
     /// Set the state of one keypad button.
diff --git a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/passphrase.rs b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/passphrase.rs
index add4d638d6..02a884cc8e 100644
--- a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/passphrase.rs
+++ b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/passphrase.rs
@@ -210,17 +210,31 @@ impl PassphraseKeyboard {
                     cancel: ButtonState::Hidden,
                     confirm: ButtonState::Disabled,
                     keys: ButtonState::Disabled,
+                    override_key: None,
                 }
             }
             _ => {
                 if self.passphrase().len() == MAX_LENGTH {
-                    // Disable all except of confirm and erase buttons
-                    KeypadState {
-                        back: ButtonState::Hidden,
-                        erase: ButtonState::Enabled,
-                        cancel: ButtonState::Hidden,
-                        confirm: ButtonState::Enabled,
-                        keys: ButtonState::Disabled,
+                    if let Some(pending_key) = self.multi_tap.pending_key() {
+                        // Disable all except of confirm, erase and the pending key
+                        KeypadState {
+                            back: ButtonState::Hidden,
+                            erase: ButtonState::Enabled,
+                            cancel: ButtonState::Hidden,
+                            confirm: ButtonState::Enabled,
+                            keys: ButtonState::Disabled,
+                            override_key: Some((pending_key, ButtonState::Enabled)),
+                        }
+                    } else {
+                        // Disable all except of confirm and erase buttons
+                        KeypadState {
+                            back: ButtonState::Hidden,
+                            erase: ButtonState::Enabled,
+                            cancel: ButtonState::Hidden,
+                            confirm: ButtonState::Enabled,
+                            keys: ButtonState::Disabled,
+                            override_key: None,
+                        }
                     }
                 } else if self.input.textbox.is_empty() {
                     // Disable all except of confirm and erase buttons
@@ -230,6 +244,7 @@ impl PassphraseKeyboard {
                         cancel: ButtonState::Hidden,
                         confirm: ButtonState::Enabled,
                         keys: ButtonState::Enabled,
+                        override_key: None,
                     }
                 } else {
                     KeypadState {
@@ -238,6 +253,7 @@ impl PassphraseKeyboard {
                         cancel: ButtonState::Hidden,
                         confirm: ButtonState::Enabled,
                         keys: ButtonState::Enabled,
+                        override_key: None,
                     }
                 }
             }
@@ -292,6 +308,7 @@ impl Component for PassphraseKeyboard {
                     .last_char_timer
                     .start(ctx, Duration::from_secs(LAST_DIGIT_TIMEOUT_S));
                 self.input.marker = false;
+                self.update_keypad_state(ctx);
                 return None;
             }
 
diff --git a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/pin.rs b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/pin.rs
index 5eaa2db041..7df653a498 100644
--- a/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/pin.rs
+++ b/core/embed/rust/src/ui/layout_eckhart/firmware/keyboard/pin.rs
@@ -73,6 +73,7 @@ impl<'a> PinKeyboard<'a> {
                     cancel: ButtonState::Hidden,
                     confirm: ButtonState::Disabled,
                     keys: ButtonState::Disabled,
+                    override_key: None,
                 }
             }
             _ => {
@@ -84,6 +85,7 @@ impl<'a> PinKeyboard<'a> {
                         cancel: ButtonState::Hidden,
                         confirm: ButtonState::Enabled,
                         keys: ButtonState::Disabled,
+                        override_key: None,
                     }
                 } else if self.input.is_empty() {
                     KeypadState {
@@ -96,6 +98,7 @@ impl<'a> PinKeyboard<'a> {
                         },
                         confirm: ButtonState::Hidden,
                         keys: ButtonState::Enabled,
+                        override_key: None,
                     }
                 } else {
                     KeypadState {
@@ -104,6 +107,7 @@ impl<'a> PinKeyboard<'a> {
                         cancel: ButtonState::Hidden,
                         confirm: ButtonState::Enabled,
                         keys: ButtonState::Enabled,
+                        override_key: None,
                     }
                 }
             }