Applications: Move to Userland/Applications/

Userland/Applications/Calculator/CMakeLists.txt

@@ -0,0 +1,11 @@
+compile_gml(CalculatorWindow.gml CalculatorGML.h calculator_gml)
+set(SOURCES
+    main.cpp
+    Calculator.cpp
+    CalculatorWidget.cpp
+    Keypad.cpp
+    CalculatorGML.h
+)
+
+serenity_app(Calculator ICON app-calculator)
+target_link_libraries(Calculator LibGUI)

Userland/Applications/Calculator/Calculator.cpp

@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Calculator.h"
+#include <AK/Assertions.h>
+#include <math.h>
+
+Calculator::Calculator()
+{
+}
+
+Calculator::~Calculator()
+{
+}
+
+double Calculator::begin_operation(Operation operation, double argument)
+{
+    double res = 0.0;
+
+    switch (operation) {
+    case Operation::None:
+        ASSERT_NOT_REACHED();
+
+    case Operation::Add:
+    case Operation::Subtract:
+    case Operation::Multiply:
+    case Operation::Divide:
+        m_saved_argument = argument;
+        m_operation_in_progress = operation;
+        return argument;
+
+    case Operation::Sqrt:
+        if (argument < 0.0) {
+            m_has_error = true;
+            return argument;
+        }
+        res = sqrt(argument);
+        clear_operation();
+        break;
+    case Operation::Inverse:
+        if (argument == 0.0) {
+            m_has_error = true;
+            return argument;
+        }
+        res = 1 / argument;
+        clear_operation();
+        break;
+    case Operation::Percent:
+        res = argument * 0.01;
+        break;
+    case Operation::ToggleSign:
+        res = -argument;
+        break;
+
+    case Operation::MemClear:
+        m_mem = 0.0;
+        res = argument;
+        break;
+    case Operation::MemRecall:
+        res = m_mem;
+        break;
+    case Operation::MemSave:
+        m_mem = argument;
+        res = argument;
+        break;
+    case Operation::MemAdd:
+        m_mem += argument;
+        res = m_mem;
+        break;
+    }
+
+    return res;
+}
+
+double Calculator::finish_operation(double argument)
+{
+    double res = 0.0;
+
+    switch (m_operation_in_progress) {
+    case Operation::None:
+        return argument;
+
+    case Operation::Add:
+        res = m_saved_argument + argument;
+        break;
+    case Operation::Subtract:
+        res = m_saved_argument - argument;
+        break;
+    case Operation::Multiply:
+        res = m_saved_argument * argument;
+        break;
+    case Operation::Divide:
+        if (argument == 0.0) {
+            m_has_error = true;
+            return argument;
+        }
+        res = m_saved_argument / argument;
+        break;
+
+    case Operation::Sqrt:
+    case Operation::Inverse:
+    case Operation::Percent:
+    case Operation::ToggleSign:
+    case Operation::MemClear:
+    case Operation::MemRecall:
+    case Operation::MemSave:
+    case Operation::MemAdd:
+        ASSERT_NOT_REACHED();
+    }
+
+    clear_operation();
+    return res;
+}
+
+void Calculator::clear_operation()
+{
+    m_operation_in_progress = Operation::None;
+    m_saved_argument = 0.0;
+    clear_error();
+}

Userland/Applications/Calculator/Calculator.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+// This type implements the regular calculator
+// behavior, such as performing arithmetic
+// operations and providing a memory cell.
+// It does not deal with number input; you
+// have to pass in already parsed double
+// values.
+
+class Calculator final {
+public:
+    Calculator();
+    ~Calculator();
+
+    enum class Operation {
+        None,
+        Add,
+        Subtract,
+        Multiply,
+        Divide,
+
+        Sqrt,
+        Inverse,
+        Percent,
+        ToggleSign,
+
+        MemClear,
+        MemRecall,
+        MemSave,
+        MemAdd
+    };
+
+    double begin_operation(Operation, double);
+    double finish_operation(double);
+
+    bool has_error() const { return m_has_error; }
+
+    void clear_operation();
+    void clear_error() { m_has_error = false; }
+
+private:
+    Operation m_operation_in_progress { Operation::None };
+    double m_saved_argument { 0.0 };
+    double m_mem { 0.0 };
+    bool m_has_error { false };
+};

Userland/Applications/Calculator/CalculatorWidget.cpp

@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * Copyright (c) 2021 Glenford Williams <gw_dev@outlook.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "CalculatorWidget.h"
+#include "Applications/Calculator/CalculatorGML.h"
+#include <AK/Assertions.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/TextBox.h>
+#include <LibGfx/Font.h>
+#include <LibGfx/FontDatabase.h>
+#include <LibGfx/Palette.h>
+
+CalculatorWidget::CalculatorWidget()
+{
+    load_from_gml(calculator_gml);
+
+    m_entry = *find_descendant_of_type_named<GUI::TextBox>("entry_textbox");
+    m_entry->set_relative_rect(5, 5, 244, 26);
+    m_entry->set_text_alignment(Gfx::TextAlignment::CenterRight);
+    m_entry->set_font(Gfx::FontDatabase::default_fixed_width_font());
+
+    m_label = *find_descendant_of_type_named<GUI::Label>("label");
+
+    m_label->set_frame_shadow(Gfx::FrameShadow::Sunken);
+    m_label->set_frame_shape(Gfx::FrameShape::Container);
+    m_label->set_frame_thickness(2);
+
+    for (int i = 0; i < 10; i++) {
+        m_digit_button[i] = *find_descendant_of_type_named<GUI::Button>(String::formatted("{}_button", i));
+        add_digit_button(*m_digit_button[i], i);
+    }
+
+    m_mem_add_button = *find_descendant_of_type_named<GUI::Button>("mem_add_button");
+    add_operation_button(*m_mem_add_button, Calculator::Operation::MemAdd);
+
+    m_mem_save_button = *find_descendant_of_type_named<GUI::Button>("mem_save_button");
+    add_operation_button(*m_mem_save_button, Calculator::Operation::MemSave);
+
+    m_mem_recall_button = *find_descendant_of_type_named<GUI::Button>("mem_recall_button");
+    add_operation_button(*m_mem_recall_button, Calculator::Operation::MemRecall);
+
+    m_mem_clear_button = *find_descendant_of_type_named<GUI::Button>("mem_clear_button");
+    add_operation_button(*m_mem_clear_button, Calculator::Operation::MemClear);
+
+    m_clear_button = *find_descendant_of_type_named<GUI::Button>("clear_button");
+    m_clear_button->on_click = [this](auto) {
+        m_keypad.set_value(0.0);
+        m_calculator.clear_operation();
+        update_display();
+    };
+
+    m_clear_error_button = *find_descendant_of_type_named<GUI::Button>("clear_error_button");
+    m_clear_error_button->on_click = [this](auto) {
+        m_keypad.set_value(0.0);
+        update_display();
+    };
+
+    m_backspace_button = *find_descendant_of_type_named<GUI::Button>("backspace_button");
+    m_backspace_button->on_click = [this](auto) {
+        m_keypad.type_backspace();
+        update_display();
+    };
+
+    m_decimal_point_button = *find_descendant_of_type_named<GUI::Button>("decimal_button");
+    m_decimal_point_button->on_click = [this](auto) {
+        m_keypad.type_decimal_point();
+        update_display();
+    };
+
+    m_sign_button = *find_descendant_of_type_named<GUI::Button>("sign_button");
+    add_operation_button(*m_sign_button, Calculator::Operation::ToggleSign);
+
+    m_add_button = *find_descendant_of_type_named<GUI::Button>("add_button");
+    add_operation_button(*m_add_button, Calculator::Operation::Add);
+
+    m_subtract_button = *find_descendant_of_type_named<GUI::Button>("subtract_button");
+    add_operation_button(*m_subtract_button, Calculator::Operation::Subtract);
+
+    m_multiply_button = *find_descendant_of_type_named<GUI::Button>("multiply_button");
+    add_operation_button(*m_multiply_button, Calculator::Operation::Multiply);
+
+    m_divide_button = *find_descendant_of_type_named<GUI::Button>("divide_button");
+    add_operation_button(*m_divide_button, Calculator::Operation::Divide);
+
+    m_sqrt_button = *find_descendant_of_type_named<GUI::Button>("sqrt_button");
+    add_operation_button(*m_sqrt_button, Calculator::Operation::Sqrt);
+
+    m_inverse_button = *find_descendant_of_type_named<GUI::Button>("inverse_button");
+    add_operation_button(*m_inverse_button, Calculator::Operation::Inverse);
+
+    m_percent_button = *find_descendant_of_type_named<GUI::Button>("mod_button");
+    add_operation_button(*m_percent_button, Calculator::Operation::Percent);
+
+    m_equals_button = *find_descendant_of_type_named<GUI::Button>("equal_button");
+    m_equals_button->on_click = [this](auto) {
+        double argument = m_keypad.value();
+        double res = m_calculator.finish_operation(argument);
+        m_keypad.set_value(res);
+        update_display();
+    };
+}
+
+CalculatorWidget::~CalculatorWidget()
+{
+}
+
+void CalculatorWidget::add_operation_button(GUI::Button& button, Calculator::Operation operation)
+{
+    button.on_click = [this, operation](auto) {
+        double argument = m_keypad.value();
+        double res = m_calculator.begin_operation(operation, argument);
+        m_keypad.set_value(res);
+        update_display();
+    };
+}
+
+void CalculatorWidget::add_digit_button(GUI::Button& button, int digit)
+{
+    button.on_click = [this, digit](auto) {
+        m_keypad.type_digit(digit);
+        update_display();
+    };
+}
+
+void CalculatorWidget::update_display()
+{
+    m_entry->set_text(m_keypad.to_string());
+    if (m_calculator.has_error())
+        m_label->set_text("E");
+    else
+        m_label->set_text("");
+}
+
+void CalculatorWidget::keydown_event(GUI::KeyEvent& event)
+{
+    //Clear button selection when we are typing
+    m_equals_button->set_focus(true);
+    m_equals_button->set_focus(false);
+
+    if (event.key() == KeyCode::Key_Return) {
+        m_keypad.set_value(m_calculator.finish_operation(m_keypad.value()));
+
+    } else if (event.key() >= KeyCode::Key_0 && event.key() <= KeyCode::Key_9) {
+        m_keypad.type_digit(atoi(event.text().characters()));
+
+    } else if (event.key() == KeyCode::Key_Period) {
+        m_keypad.type_decimal_point();
+
+    } else if (event.key() == KeyCode::Key_Escape) {
+        m_keypad.set_value(0.0);
+        m_calculator.clear_operation();
+
+    } else if (event.key() == KeyCode::Key_Backspace) {
+        m_keypad.type_backspace();
+
+    } else {
+        Calculator::Operation operation;
+
+        switch (event.key()) {
+        case KeyCode::Key_Plus:
+            operation = Calculator::Operation::Add;
+            break;
+        case KeyCode::Key_Minus:
+            operation = Calculator::Operation::Subtract;
+            break;
+        case KeyCode::Key_Asterisk:
+            operation = Calculator::Operation::Multiply;
+            break;
+        case KeyCode::Key_Slash:
+            operation = Calculator::Operation::Divide;
+            break;
+        case KeyCode::Key_Percent:
+            operation = Calculator::Operation::Percent;
+            break;
+        default:
+            return;
+        }
+
+        m_keypad.set_value(m_calculator.begin_operation(operation, m_keypad.value()));
+    }
+
+    update_display();
+}

Userland/Applications/Calculator/CalculatorWidget.h

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * Copyright (c) 2021 Glenford Williams <gw_dev@outlook.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Calculator.h"
+#include "Keypad.h"
+#include <AK/Vector.h>
+#include <LibGUI/Widget.h>
+
+class CalculatorWidget final : public GUI::Widget {
+    C_OBJECT(CalculatorWidget)
+public:
+    virtual ~CalculatorWidget() override;
+
+private:
+    CalculatorWidget();
+    void add_operation_button(GUI::Button&, Calculator::Operation);
+    void add_digit_button(GUI::Button&, int digit);
+
+    void update_display();
+
+    virtual void keydown_event(GUI::KeyEvent&) override;
+
+    Calculator m_calculator;
+    Keypad m_keypad;
+
+    RefPtr<GUI::TextBox> m_entry;
+    RefPtr<GUI::Label> m_label;
+
+    RefPtr<GUI::Button> m_digit_button[10];
+    RefPtr<GUI::Button> m_mem_add_button;
+    RefPtr<GUI::Button> m_mem_save_button;
+    RefPtr<GUI::Button> m_mem_recall_button;
+    RefPtr<GUI::Button> m_mem_clear_button;
+    RefPtr<GUI::Button> m_clear_button;
+    RefPtr<GUI::Button> m_clear_error_button;
+    RefPtr<GUI::Button> m_backspace_button;
+    RefPtr<GUI::Button> m_decimal_point_button;
+    RefPtr<GUI::Button> m_sign_button;
+    RefPtr<GUI::Button> m_add_button;
+    RefPtr<GUI::Button> m_subtract_button;
+    RefPtr<GUI::Button> m_multiply_button;
+    RefPtr<GUI::Button> m_divide_button;
+    RefPtr<GUI::Button> m_sqrt_button;
+    RefPtr<GUI::Button> m_inverse_button;
+    RefPtr<GUI::Button> m_percent_button;
+    RefPtr<GUI::Button> m_equals_button;
+};

Userland/Applications/Calculator/CalculatorWindow.gml

@@ -0,0 +1,272 @@
+@GUI::Widget {
+    fixed_width: 254
+    fixed_height: 213
+    fill_with_background_color: true
+
+    layout: @GUI::VerticalBoxLayout {
+        margins: [10, 0, 10, 0]
+    }
+
+    @GUI::TextBox {
+        name: "entry_textbox"
+    }
+
+    @GUI::Widget {
+        layout: @GUI::HorizontalBoxLayout {
+        }
+
+        @GUI::Label {
+            name: "label"
+            fixed_width: 35
+            fixed_height: 27
+        }
+
+        @GUI::Widget {
+            fixed_width: 5
+        }
+
+        @GUI::Button {
+            name: "backspace_button"
+            text: "Backspace"
+            fixed_width: 65
+            fixed_height: 28
+            foreground_color: "brown"
+        }
+
+        @GUI::Button {
+            name: "clear_error_button"
+            text: "CE"
+            fixed_width: 55
+            fixed_height: 28
+            foreground_color: "brown"
+        }
+
+        @GUI::Button {
+            name: "clear_button"
+            text: "C"
+            fixed_width: 60
+            fixed_height: 28
+            foreground_color: "brown"
+        }
+    }
+
+    @GUI::Widget {
+        layout: @GUI::HorizontalBoxLayout {
+        }
+
+        @GUI::Button {
+            name: "mem_clear_button"
+            text: "MC"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "red"
+        }
+
+        @GUI::Widget {
+            fixed_width: 5
+        }
+
+        @GUI::Button {
+            name: "7_button"
+            text: "7"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "8_button"
+            text: "8"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "9_button"
+            text: "9"
+            fixed_width: 35
+            fixed_height: 28
+        }
+
+        @GUI::Button {
+            name: "divide_button"
+            text: "/"
+            fixed_width: 35
+            fixed_height: 28
+        }
+
+        @GUI::Button {
+            name: "sqrt_button"
+            text: "sqrt"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+    }
+
+    @GUI::Widget {
+        layout: @GUI::HorizontalBoxLayout {}
+
+        @GUI::Button {
+            name: "mem_recall_button"
+            text: "MR"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "red"
+        }
+
+        @GUI::Widget {
+            fixed_width: 5
+        }
+
+        @GUI::Button {
+            name: "4_button"
+            text: "4"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "5_button"
+            text: "5"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "6_button"
+            text: "6"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "multiply_button"
+            text: "*"
+            fixed_width: 35
+            fixed_height: 28
+        }
+
+        @GUI::Button {
+            name: "mod_button"
+            text: "%"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+    }
+
+    @GUI::Widget {
+        layout: @GUI::HorizontalBoxLayout {}
+
+        @GUI::Button {
+            name: "mem_save_button"
+            text: "MS"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "red"
+        }
+
+        @GUI::Widget {
+            fixed_width: 5
+        }
+
+        @GUI::Button {
+            name: "1_button"
+            text: "1"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "2_button"
+            text: "2"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "3_button"
+            text: "3"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "subtract_button"
+            text: "-"
+            fixed_width: 35
+            fixed_height: 28
+        }
+
+        @GUI::Button {
+            name: "inverse_button"
+            text: "1/x"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+    }
+
+    @GUI::Widget {
+        layout: @GUI::HorizontalBoxLayout {}
+
+        @GUI::Button {
+            name: "mem_add_button"
+            text: "M+"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "red"
+        }
+
+        @GUI::Widget {
+            fixed_width: 5
+        }
+
+        @GUI::Button {
+            name: "0_button"
+            text: "0"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "sign_button"
+            text: "+/-"
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "decimal_button"
+            text: "."
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "blue"
+        }
+
+        @GUI::Button {
+            name: "add_button"
+            text: "+"
+            fixed_width: 35
+            fixed_height: 28
+        }
+
+        @GUI::Button {
+            name: "equal_button"
+            text: "="
+            fixed_width: 35
+            fixed_height: 28
+            foreground_color: "red"
+        }
+    }
+}

Userland/Applications/Calculator/Keypad.cpp

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Keypad.h"
+#include <AK/StringBuilder.h>
+#include <math.h>
+
+Keypad::Keypad()
+{
+}
+
+Keypad::~Keypad()
+{
+}
+
+void Keypad::type_digit(int digit)
+{
+    switch (m_state) {
+    case State::External:
+        m_state = State::TypingInteger;
+        m_negative = false;
+        m_int_value = digit;
+        m_frac_value = 0;
+        m_frac_length = 0;
+        break;
+    case State::TypingInteger:
+        ASSERT(m_frac_value == 0);
+        ASSERT(m_frac_length == 0);
+        m_int_value *= 10;
+        m_int_value += digit;
+        break;
+    case State::TypingDecimal:
+        if (m_frac_length > 6)
+            break;
+        m_frac_value *= 10;
+        m_frac_value += digit;
+        m_frac_length++;
+        break;
+    }
+}
+
+void Keypad::type_decimal_point()
+{
+    switch (m_state) {
+    case State::External:
+        m_negative = false;
+        m_int_value = 0;
+        m_frac_value = 0;
+        m_frac_length = 0;
+        break;
+    case State::TypingInteger:
+        ASSERT(m_frac_value == 0);
+        ASSERT(m_frac_length == 0);
+        m_state = State::TypingDecimal;
+        break;
+    case State::TypingDecimal:
+        // Ignore it.
+        break;
+    }
+}
+
+void Keypad::type_backspace()
+{
+    switch (m_state) {
+    case State::External:
+        m_negative = false;
+        m_int_value = 0;
+        m_frac_value = 0;
+        m_frac_length = 0;
+        break;
+    case State::TypingDecimal:
+        if (m_frac_length > 0) {
+            m_frac_value /= 10;
+            m_frac_length--;
+            break;
+        }
+        ASSERT(m_frac_value == 0);
+        m_state = State::TypingInteger;
+        [[fallthrough]];
+    case State::TypingInteger:
+        ASSERT(m_frac_value == 0);
+        ASSERT(m_frac_length == 0);
+        m_int_value /= 10;
+        if (m_int_value == 0)
+            m_negative = false;
+        break;
+    }
+}
+
+double Keypad::value() const
+{
+    double res = 0.0;
+
+    long frac = m_frac_value;
+    for (int i = 0; i < m_frac_length; i++) {
+        int digit = frac % 10;
+        res += digit;
+        res /= 10.0;
+        frac /= 10;
+    }
+
+    res += m_int_value;
+    if (m_negative)
+        res = -res;
+
+    return res;
+}
+
+void Keypad::set_value(double value)
+{
+    m_state = State::External;
+
+    if (value < 0.0) {
+        m_negative = true;
+        value = -value;
+    } else
+        m_negative = false;
+
+    m_int_value = value;
+    value -= m_int_value;
+
+    m_frac_value = 0;
+    m_frac_length = 0;
+    while (value != 0) {
+        value *= 10.0;
+        int digit = value;
+        m_frac_value *= 10;
+        m_frac_value += digit;
+        m_frac_length++;
+        value -= digit;
+
+        if (m_frac_length > 6)
+            break;
+    }
+}
+
+String Keypad::to_string() const
+{
+    StringBuilder builder;
+    if (m_negative)
+        builder.append("-");
+    builder.appendff("{}", m_int_value);
+
+    if (m_frac_length > 0)
+        builder.appendff(".{:0{}}", m_frac_value, m_frac_length);
+
+    return builder.to_string();
+}

Userland/Applications/Calculator/Keypad.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/String.h>
+
+// This type implements number typing and
+// displaying mechanics. It does not perform
+// any arithmetic operations or anything on
+// the values it deals with.
+
+class Keypad final {
+public:
+    Keypad();
+    ~Keypad();
+
+    void type_digit(int digit);
+    void type_decimal_point();
+    void type_backspace();
+
+    double value() const;
+    void set_value(double);
+
+    String to_string() const;
+
+private:
+    // Internal representation of the current decimal value.
+    bool m_negative { false };
+    long m_int_value { 0 };
+    long m_frac_value { 0 };
+    int m_frac_length { 0 };
+    // E.g. for -35.004200,
+    // m_negative = true
+    // m_int_value = 35
+    // m_frac_value = 4200
+    // m_frac_length = 6
+
+    enum class State {
+        External,
+        TypingInteger,
+        TypingDecimal
+    };
+
+    State m_state { State::External };
+};

Userland/Applications/Calculator/main.cpp

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "CalculatorWidget.h"
+#include <LibGUI/Action.h>
+#include <LibGUI/Application.h>
+#include <LibGUI/Icon.h>
+#include <LibGUI/Menu.h>
+#include <LibGUI/MenuBar.h>
+#include <LibGUI/Window.h>
+#include <LibGfx/Bitmap.h>
+#include <stdio.h>
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio shared_buffer rpath accept unix cpath fattr", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    auto app = GUI::Application::construct(argc, argv);
+
+    if (pledge("stdio shared_buffer rpath accept", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    if (unveil("/res", "r") < 0) {
+        perror("unveil");
+        return 1;
+    }
+
+    unveil(nullptr, nullptr);
+
+    auto app_icon = GUI::Icon::default_icon("app-calculator");
+
+    auto window = GUI::Window::construct();
+    window->set_title("Calculator");
+    window->set_resizable(false);
+    window->resize(254, 213);
+
+    window->set_main_widget<CalculatorWidget>();
+
+    window->show();
+    window->set_icon(app_icon.bitmap_for_size(16));
+
+    auto menubar = GUI::MenuBar::construct();
+
+    auto& app_menu = menubar->add_menu("Calculator");
+    app_menu.add_action(GUI::CommonActions::make_quit_action([](auto&) {
+        GUI::Application::the()->quit();
+        return;
+    }));
+
+    auto& help_menu = menubar->add_menu("Help");
+    help_menu.add_action(GUI::CommonActions::make_about_action("Calculator", app_icon));
+
+    app->set_menubar(move(menubar));
+
+    return app->exec();
+}