Keyboard UX/UI: Access to caps lock - clearer icons

selfdrive/ui/qt/widgets/keyboard.cc

@@ -1,6 +1,7 @@
 #include "selfdrive/ui/qt/widgets/keyboard.h"
 
 #include <vector>
+#include <QDateTime>
 
 #include <QButtonGroup>
 #include <QHBoxLayout>
@@ -10,10 +11,12 @@
 
 const QString BACKSPACE_KEY = "⌫";
 const QString ENTER_KEY = "→";
+const QString SHIFT_KEY = "⇧";
+const QString CAPS_LOCK_KEY = "⇪";
 
 const QMap<QString, int> KEY_STRETCH = {{"  ", 3}, {ENTER_KEY, 2}};
 
-const QStringList CONTROL_BUTTONS = {"↑", "↓", "ABC", "#+=", "123", BACKSPACE_KEY, ENTER_KEY};
+const QStringList CONTROL_BUTTONS = {SHIFT_KEY, CAPS_LOCK_KEY, "ABC", "#+=", "123", BACKSPACE_KEY, ENTER_KEY};
 
 const float key_spacing_vertical = 20;
 const float key_spacing_horizontal = 15;
@@ -106,7 +109,7 @@ Keyboard::Keyboard(QWidget *parent) : QFrame(parent) {
   std::vector<QVector<QString>> lowercase = {
     {"q", "w", "e", "r", "t", "y", "u", "i", "o", "p"},
     {"a", "s", "d", "f", "g", "h", "j", "k", "l"},
-    {"↑", "z", "x", "c", "v", "b", "n", "m", BACKSPACE_KEY},
+    {SHIFT_KEY, "z", "x", "c", "v", "b", "n", "m", BACKSPACE_KEY},
     {"123", "/", "-", "  ", ".", ENTER_KEY},
   };
   main_layout->addWidget(new KeyboardLayout(this, lowercase));
@@ -115,8 +118,8 @@ Keyboard::Keyboard(QWidget *parent) : QFrame(parent) {
   std::vector<QVector<QString>> uppercase = {
     {"Q", "W", "E", "R", "T", "Y", "U", "I", "O", "P"},
     {"A", "S", "D", "F", "G", "H", "J", "K", "L"},
-    {"↓", "Z", "X", "C", "V", "B", "N", "M", BACKSPACE_KEY},
-    {"123", "  ", ".", ENTER_KEY},
+    {SHIFT_KEY, "Z", "X", "C", "V", "B", "N", "M", BACKSPACE_KEY},
+    {"123", "/", "-", "  ", ".", ENTER_KEY},
   };
   main_layout->addWidget(new KeyboardLayout(this, uppercase));
 
@@ -141,25 +144,41 @@ Keyboard::Keyboard(QWidget *parent) : QFrame(parent) {
   main_layout->setCurrentIndex(0);
 }
 
+void Keyboard::handleCapsPress() {
+  bool is_double_tap = (QDateTime::currentMSecsSinceEpoch() - last_shift_key_press) <= DOUBLE_TAP_THRESHOLD_MS;
+  last_shift_key_press = QDateTime::currentMSecsSinceEpoch();
+
+  bool was_locked = caps_lock_on;
+  caps_lock_on = !was_locked && is_double_tap;
+  main_layout->setCurrentIndex(caps_lock_on || (!was_locked && main_layout->currentIndex() == 0));
+
+  for (KeyButton* btn : main_layout->currentWidget()->findChildren<KeyButton*>()) {
+    if (btn->text() == SHIFT_KEY || btn->text() == CAPS_LOCK_KEY) {
+      btn->setText(caps_lock_on ? CAPS_LOCK_KEY : SHIFT_KEY);
+      btn->setStyleSheet(main_layout->currentIndex() == 1 ? "background-color: #465BEA;" : "");
+    }
+  }
+}
+
 void Keyboard::handleButton(QAbstractButton* btn) {
   const QString &key = btn->text();
   if (CONTROL_BUTTONS.contains(key)) {
-    if (key == "↓" || key == "ABC") {
+    if (key == "ABC") {
+      caps_lock_on = false;
       main_layout->setCurrentIndex(0);
-    } else if (key == "↑") {
-      main_layout->setCurrentIndex(1);
+    } else if (key == SHIFT_KEY || key == CAPS_LOCK_KEY) {
+      handleCapsPress();
     } else if (key == "123") {
       main_layout->setCurrentIndex(2);
     } else if (key == "#+=") {
       main_layout->setCurrentIndex(3);
     } else if (key == ENTER_KEY) {
-      main_layout->setCurrentIndex(0);
       emit emitEnter();
     } else if (key == BACKSPACE_KEY) {
       emit emitBackspace();
     }
   } else {
-    if ("A" <= key && key <= "Z") {
+    if (!caps_lock_on && "A" <= key && key <= "Z") {
       main_layout->setCurrentIndex(0);
     }
     emit emitKey(key);

selfdrive/ui/qt/widgets/keyboard.h

@@ -29,9 +29,13 @@ class Keyboard : public QFrame {
 
 private:
   QStackedLayout* main_layout;
+  bool caps_lock_on = false;
+  qint64 last_shift_key_press = 0;
+  static const int DOUBLE_TAP_THRESHOLD_MS = 250;
 
 private slots:
   void handleButton(QAbstractButton* m_button);
+  void handleCapsPress();
 
 signals:
   void emitKey(const QString &s);