frontend/applets: frontend swkbd base

Original commits by @jroweboy:

* Rebase out the other commit

* changing branches

* More work on stuff and things ecks DEE

Changes by @zhaowenlan1779:

* Removed #include of result.h

src/core/frontend/applet/interface.cpp

@@ -0,0 +1,20 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <unordered_map>
+#include "core/frontend/interface.h"
+
+namespace Frontend {
+
+std::unordered_map<AppletType, std::shared_ptr<AppletInterface>> registered_applets;
+
+void RegisterFrontendApplet(std::shared_ptr<AppletInterface> applet, AppletType type) {
+    registered_applets[type] = applet;
+}
+
+void UnregisterFrontendApplet(AppletType type) {
+    registered_applets.erase(type);
+}
+
+} // namespace Frontend

src/core/frontend/applet/interface.h

@@ -0,0 +1,66 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+#include <memory>
+
+namespace Frontend {
+
+enum class AppletType {
+    SoftwareKeyboard,
+};
+
+class AppletConfig {};
+class AppletData {};
+
+class AppletInterface {
+public:
+    virtual ~AppletInterface() = default;
+
+    /**
+     * On applet start, the applet specific configuration will be passed in along with the
+     * framebuffer.
+     */
+    // virtual void Setup(const Config* /*,  framebuffer */) = 0;
+
+    /**
+     * Called on a fixed schedule to have the applet update any state such as the framebuffer.
+     */
+    virtual void Update() = 0;
+
+    /**
+     * Checked every update to see if the applet is still running. When the applet is done, the core
+     * will call ReceiveData
+     */
+    virtual bool IsRunning() {
+        return running;
+    }
+
+private:
+    // framebuffer;
+    std::atomic_bool running = false;
+};
+
+/**
+ * Frontends call this method to pass a frontend applet implementation to the core. If the core
+ * already has a applet registered, then this replaces the old applet
+ *
+ * @param applet - Frontend Applet implementation that the HLE applet code will launch
+ * @param type - Which type of applet
+ */
+void RegisterFrontendApplet(std::shared_ptr<AppletInterface> applet, AppletType type);
+
+/**
+ * Frontends call this to prevent future requests
+ */
+void UnregisterFrontendApplet(AppletType type);
+
+/**
+ * Returns the Frontend Applet for the provided type
+ */
+std::shared_ptr<AppletInterface> GetRegisteredApplet(AppletType type);
+
+} // namespace Frontend

src/core/frontend/applet/swkbd.cpp

@@ -0,0 +1,127 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/frontend/applet/swkbd.h"
+
+namespace Frontend {
+
+ValidationError SoftwareKeyboard::ValidateFilters(const std::string& input) {
+    if (config.filters.prevent_digit) {
+        if (std::any_of(input.begin(), input.end(), std::isdigit)) {
+            return ValidationError::DigitNotAllowed;
+        }
+    }
+    if (config.filters.prevent_at) {
+        if (input.find('@') != std::string::npos) {
+            return ValidationError::AtSignNotAllowed;
+        }
+    }
+    if (config.filters.prevent_percent) {
+        if (input.find('%') != std::string::npos) {
+            return ValidationError::PercentNotAllowed;
+        }
+    }
+    if (config.filter.prevent_backslash) {
+        if (input.find('\\') != std::string::npos) {
+            return ValidationError::BackslashNotAllowed;
+        }
+    }
+    if (config.filters.prevent_profanity) {
+        // TODO: check the profanity filter
+        LOG_INFO(Frontend, "App requested swkbd profanity filter, but its not implemented.");
+    }
+    if (config.filters.enable_callback) {
+        // TODO: check the callback
+        LOG_INFO(Frontend, "App requested a swkbd callback, but its not implemented.");
+    }
+    return valid;
+}
+
+ValidationError SoftwareKeyboard::ValidateInput(const std::string& input) {
+    ValidationError error;
+    if ((error = ValidateFilters(input)) != ValidationError::None) {
+        return error;
+    }
+
+    // TODO(jroweboy): Is max_text_length inclusive or exclusive?
+    if (input.size() > config.max_text_length) {
+        return ValidationError::MaxLengthExceeded;
+    }
+
+    auto is_blank = [&] { return std::all_of(input.begin(), input.end(), std::isspace); };
+    auto is_empty = [&] { return input.empty(); };
+    switch (config.valid_input) {
+    case AcceptedInput::FixedLength:
+        if (input.size() != config.max_text_length) {
+            return ValidationError::FixedLengthRequired;
+        }
+        break;
+    case AcceptedInput::NotEmptyAndNotBlank:
+        if (is_blank()) {
+            return ValidationError::BlankInputNotAllowed;
+        }
+        if (is_empty()) {
+            return ValidationError::EmptyInputNotAllowed;
+        }
+        break;
+    case AcceptedInput::NotBlank:
+        if (is_blank()) {
+            return ValidationError::BlankInputNotAllowed;
+        }
+        break;
+    case AcceptedInput::NotEmpty:
+        if (is_empty()) {
+            return ValidationError::EmptyInputNotAllowed;
+        }
+        break;
+    case AcceptedInput::Anything:
+        return ValidationError::None;
+    default:
+        // TODO(jroweboy): What does hardware do in this case?
+        NGLOG_CRITICAL(Frontend, "Application requested unknown validation method. Method: {}",
+                       static_cast<u32>(config.valid_input));
+        UNREACHABLE();
+    }
+
+    return ValidationError::None;
+} // namespace Frontend
+
+ValidationError SoftwareKeyboard::ValidateButton(u8 button) {
+    switch (config.button_config) {
+    case ButtonConfig::None:
+        return ValidationError::None;
+    case ButtonConfig::Single:
+        if (button != 0) {
+            return ValidationError::ButtonOutOfRange;
+        }
+        break;
+    case ButtonConfig::Dual:
+        if (button > 1) {
+            return ValidationError::ButtonOutOfRange;
+        }
+        break;
+    case ButtonConfig::Triple:
+        if (button > 2) {
+            return ValidationError::ButtonOutOfRange;
+        }
+        break;
+    default:
+        UNREACHABLE();
+    }
+    return ValidationError::None;
+}
+
+ValidationError Finalize(cosnt std::string& text, u8 button) {
+    ValidationError error;
+    if ((error = ValidateInput(text)) != ValidationError::NONE) {
+        return error;
+    }
+    if ((error = ValidateButton(button)) != ValidationError::NONE) {
+        return error;
+    }
+    data = {text, button};
+    running = false;
+}
+
+} // namespace Frontend

src/core/frontend/applet/swkbd.h

@@ -0,0 +1,123 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <unordered_map>
+#include "core/frontend/applet/interface.h"
+
+namespace Frontend {
+
+enum class AcceptedInput {
+    Anything = 0,        /// All inputs are accepted.
+    NotEmpty,            /// Empty inputs are not accepted.
+    NotEmptyAndNotBlank, /// Empty or blank inputs (consisting solely of whitespace) are not
+                         /// accepted.
+    NotBlank,    /// Blank inputs (consisting solely of whitespace) are not accepted, but empty
+                 /// inputs are.
+    FixedLength, /// The input must have a fixed length (specified by maxTextLength in
+                 /// swkbdInit).
+};
+
+enum class ButtonConfig {
+    Single = 0, /// Ok button
+    Dual,       /// Cancel | Ok buttons
+    Triple,     /// Cancel | I Forgot | Ok buttons
+    None,       /// No button (returned by swkbdInputText in special cases)
+};
+
+/// Default English button text mappings. Frontends may need to copy this to internationalize it.
+static const char* BUTTON_OKAY = "Ok";
+static const char* BUTTON_CANCEL = "Cancel";
+static const char* BUTTON_FORGOT = "I Forgot";
+static const std::unordered_map<ButtonConfig, std::vector<std::string>> DEFAULT_BUTTON_MAPPING = {
+    {ButtonConfig::Single, {BUTTON_OKAY}},
+    {ButtonConfig::Dual, {BUTTON_CANCEL, BUTTON_OKAY}},
+    {ButtonConfig::Triple, {BUTTON_CANCEL, BUTTON_FORGOT, BUTTON_OKAY}},
+};
+
+/// Configuration thats relevent to frontend implementation of applets. Anything missing that we
+/// later learn is needed can be added here and filled in by the backed HLE applet
+struct KeyboardConfig {
+    ButtonConfig button_config;
+    AcceptedInput accept_mode;   /// What kinds of input are accepted (blank/empty/fixed width)
+    bool multiline_mode;         /// True if the keyboard accepts multiple lines of input
+    u16 max_text_length;         /// Maximum number of letters allowed if its a text input
+    u16 max_digits;              /// Maximum number of numbers allowed if its a number input
+    std::string hint_text;       /// Displayed in the field as a hint before
+    bool has_custom_button_text; /// If true, use the button_text instead
+    std::vector<std::string> button_text; /// Contains the button text that the caller provides
+    struct Filters {
+        bool prevent_digit;   /// Disallow the use of more than a certain number of digits (TODO how
+                              /// many is a certain number)
+        bool prevent_at;      /// Disallow the use of the @ sign.
+        bool prevent_percent; /// Disallow the use of the % sign.
+        bool prevent_backslash; /// Disallow the use of the \ sign.
+        bool prevent_profanity; /// Disallow profanity using Nintendo's profanity filter.
+        bool enable_callback;   /// Use a callback in order to check the input.
+    } filters;
+};
+
+struct KeyboardData {
+    std::string text;
+    u8 button;
+};
+
+enum class ValidationError {
+    None,
+    // Button Selection
+    ButtonOutOfRange,
+    // Configured Filters
+    DigitNotAllowed,
+    AtSignNotAllowed,
+    PercentNotAllowed,
+    BackslashNotAllowed,
+    ProfanityNotAllowed,
+    CallbackFailed,
+    // Allowed Input Type
+    FixedLengthRequired,
+    BlankInputNotAllowed,
+    EmptyInputNotAllowed,
+};
+
+class SoftwareKeyboard : public AppletInterface {
+public:
+    explict SoftwareKeyboard(KeyboardConfig config) : AppletInterface(), config(config) {}
+
+protected:
+    /**
+     * Validates if the provided string breaks any of the filter rules. This is meant to be called
+     * whenever the user input changes to check to see if the new input is valid. Frontends can
+     * decide if they want to check the input continuously or once before submission
+     */
+    ValidationError ValidateFilters(const std::string& input);
+
+    /**
+     * Validates the the provided string doesn't break any extra rules like "input must not be
+     * empty". This will be called by Finalize but can be called earlier if the frontend needs
+     */
+    ValidationError ValidateInput(const std::string& input);
+
+    /**
+     * Verifies that the selected button is valid. This should be used as the last check before
+     * closing.
+     */
+    ValidationError ValidateButton(u8 button);
+
+    /**
+     * Runs all validation phases. If successful, stores the data so that the HLE applet in core can
+     * send this to the calling application
+     */
+    ValidationError Finialize(const std::string&, u8 button);
+
+private:
+    KeyboardData ReceiveData() override {
+        return data;
+    }
+
+    KeyboardConfig config;
+    KeyboardData data;
+};
+
+} // namespace Frontend