spk_text_edit.hpp

// spk_text_edit.hpp
#pragma once
 
#include <functional>
#include <string>
 
#include "structure/container/spk_task_result.hpp"
#include "structure/design_pattern/spk_observable_value.hpp"
#include "structure/graphics/painter/spk_color_painter.hpp"
#include "structure/system/event/spk_system_event.hpp"
#include "structure/system/time/spk_duration.hpp"
#include "structure/system/time/spk_timestamp.hpp"
#include "structure/widget/components/spk_nine_slice_background.hpp"
#include "structure/widget/components/spk_text_region.hpp"
#include "structure/widget/spk_widget.hpp"
 
namespace spk
{
    class TextEdit : public spk::Widget
    {
    public:
        enum class ValidationState
        {
            Valid,
            Invalid,
            Undefined
        };

        using ValidationStatus = spk::TaskResult<ValidationState>;

        using ValidationCallback = std::function<ValidationStatus(const std::wstring &)>;

        using EditionContract = spk::ObservableValue<std::wstring>::Contract;
        using EditionJob = spk::ObservableValue<std::wstring>::Job;
 
    private:
        NineSliceBackground _background;
        TextRegion _textRegion;
        TextRegion _placeholderRegion;
 
        spk::ColorPainter _cursorPainter;
        spk::ColorMesh _cursorMesh;
        spk::ColorMesh::Builder _cursorMeshBuilder;
 
        spk::Color _cursorColor{1.0f, 1.0f, 1.0f, 1.0f};
        size_t _cursorWidth = 2;
        spk::Duration _cursorBlinkDuration{500, spk::TimeUnit::Millisecond};
        bool _cursorVisible = true;
        spk::Timestamp _lastBlinkTimestamp{};
 
        spk::ObservableValue<std::wstring> _text;
        std::wstring _placeholder;
        size_t _cursorPosition = 0;
        bool _obscured = false;
 
        ValidationCallback _validationCallback;
 
    private:
        void _updateLayoutFromGeometry();
        void _updateDisplayedText();
        void _updateCaret();
 
        void _refreshCursor();
        void _resetCursorBlinkState();
        void _updateCursorBlinkState();
 
        ValidationStatus _validateText(const std::wstring &p_text) const;
 
        void _applyTextNoValidation(const std::wstring &p_text, size_t p_cursorPosition);
        ValidationStatus _applyValidatedText(const std::wstring &p_text, size_t p_cursorPosition);
 
    protected:
        void _onGeometryChange() override;
        void _onPaintEvent(spk::PaintEvent &p_event) override;

        void _onMouseMotionEvent(spk::MouseMotionEvent &p_event) override;
        void _onMousePressEvent(spk::MousePressEvent &p_event) override;
        void _onMouseReleaseEvent(spk::MouseReleaseEvent &p_event) override;

        void _onGlyphEvent(spk::GlyphEvent &p_event) override;
        void _onKeyPressEvent(spk::KeyPressEvent &p_event) override;
        void _onFocusEvent(spk::FocusEvent &p_event) override;
 
    public:
        TextEdit(const std::wstring &p_name, spk::Widget *p_parent);

        void setCornerSize(const spk::Vector2UInt &p_cornerSize);
        const spk::Vector2UInt &cornerSize() const;

        void setTexture(const spk::SpriteSheet *p_spriteSheet);
        const spk::SpriteSheet *texture() const;

        void setFont(spk::Font *p_font);
        spk::Font *font() const;

        void setFontSize(const spk::Font::Size &p_size);
        const spk::Font::Size &fontSize() const;

        void setColors(const spk::Color &p_glyphColor, const spk::Color &p_outlineColor);
        const spk::Color &glyphColor() const;
        const spk::Color &outlineColor() const;

        void setPlaceholder(const std::wstring &p_placeholder);
        const std::wstring &placeholder() const;

        void setValidationCallback(ValidationCallback p_callback);
        const ValidationCallback &validationCallback() const;

        ValidationStatus checkTextValidity(const std::wstring &p_text) const;

        const std::wstring &text() const;

        ValidationStatus setText(const std::wstring &p_text);

        EditionContract subscribeToEdition(const EditionJob &p_job);

        void setAlignment(HorizontalAlignment p_horizontalAlignment, VerticalAlignment p_verticalAlignment);
 
        // Cursor
        void placeCursor(size_t p_position);
        void moveCursor(int p_delta);
        size_t cursorPosition() const;
 
        // Misc
        void clear();
        void setObscured(bool p_obscured);
        bool obscured() const;

        void setCursorBlinkDuration(const spk::Duration &p_duration);
        const spk::Duration &cursorBlinkDuration() const;
    };
}