Calculator: Utilize Button mimic_pressed to show when keys are pressed

Userland/Applications/Calculator/CalculatorWidget.cpp

@@ -10,6 +10,7 @@
 #include "CalculatorWidget.h"
 #include "KeypadValue.h"
 #include <Applications/Calculator/CalculatorGML.h>
+#include <LibCore/Event.h>
 #include <LibGUI/Button.h>
 #include <LibGUI/Label.h>
 #include <LibGUI/TextBox.h>
@@ -134,6 +135,20 @@ void CalculatorWidget::set_entry(KeypadValue value)
     update_display();
 }
 
+void CalculatorWidget::mimic_pressed_button(RefPtr<GUI::Button> button)
+{
+    constexpr int TIMER_MS = 80;
+
+    if (!m_mimic_pressed_button.is_null())
+        m_mimic_pressed_button->set_mimic_pressed(false);
+
+    button->set_mimic_pressed(true);
+    m_mimic_pressed_button = button;
+
+    stop_timer();
+    start_timer(TIMER_MS, Core::TimerShouldFireWhenNotVisible::Yes);
+}
+
 void CalculatorWidget::update_display()
 {
     m_entry->set_text(m_keypad.to_string());
@@ -151,33 +166,44 @@ void CalculatorWidget::keydown_event(GUI::KeyEvent& event)
 
     if (event.key() == KeyCode::Key_Return || event.key() == KeyCode::Key_Equal) {
         m_keypad.set_value(m_calculator.finish_operation(m_keypad.value()));
+        mimic_pressed_button(m_equals_button);
     } else if (event.code_point() >= '0' && event.code_point() <= '9') {
-        m_keypad.type_digit(event.code_point() - '0');
+        u32 digit = event.code_point() - '0';
+        m_keypad.type_digit(digit);
+        mimic_pressed_button(m_digit_button[digit]);
     } else if (event.code_point() == '.') {
         m_keypad.type_decimal_point();
+        mimic_pressed_button(m_decimal_point_button);
     } else if (event.key() == KeyCode::Key_Escape) {
         m_keypad.set_value(0.0);
         m_calculator.clear_operation();
+        mimic_pressed_button(m_clear_button);
     } else if (event.key() == KeyCode::Key_Backspace) {
         m_keypad.type_backspace();
+        mimic_pressed_button(m_backspace_button);
     } else {
         Calculator::Operation operation;
 
         switch (event.code_point()) {
         case '+':
             operation = Calculator::Operation::Add;
+            mimic_pressed_button(m_add_button);
             break;
         case '-':
             operation = Calculator::Operation::Subtract;
+            mimic_pressed_button(m_subtract_button);
             break;
         case '*':
             operation = Calculator::Operation::Multiply;
+            mimic_pressed_button(m_multiply_button);
             break;
         case '/':
             operation = Calculator::Operation::Divide;
+            mimic_pressed_button(m_divide_button);
             break;
         case '%':
             operation = Calculator::Operation::Percent;
+            mimic_pressed_button(m_percent_button);
             break;
         default:
             return;
@@ -188,3 +214,9 @@ void CalculatorWidget::keydown_event(GUI::KeyEvent& event)
 
     update_display();
 }
+
+void CalculatorWidget::timer_event(Core::TimerEvent&)
+{
+    if (!m_mimic_pressed_button.is_null())
+        m_mimic_pressed_button->set_mimic_pressed(false);
+}

Userland/Applications/Calculator/CalculatorWidget.h

@@ -26,9 +26,11 @@ private:
     void add_operation_button(GUI::Button&, Calculator::Operation);
     void add_digit_button(GUI::Button&, int digit);
 
+    void mimic_pressed_button(RefPtr<GUI::Button>);
     void update_display();
 
     virtual void keydown_event(GUI::KeyEvent&) override;
+    virtual void timer_event(Core::TimerEvent&) override;
 
     Calculator m_calculator;
     Keypad m_keypad;
@@ -54,4 +56,6 @@ private:
     RefPtr<GUI::Button> m_inverse_button;
     RefPtr<GUI::Button> m_percent_button;
     RefPtr<GUI::Button> m_equals_button;
+
+    RefPtr<GUI::Button> m_mimic_pressed_button {};
 };