IView.h

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#pragma once
 
#include <cstdint>
 
namespace cdc::ui {

enum class InputResult : uint8_t {
    CONSUMED,       // Input was handled, may need re-render
    IGNORED,        // Input was not handled
    REQUEST_POP,    // View wants to be popped (back/cancel)
    REQUEST_PUSH    // View wants to push a child view
};

class IView {
public:
    virtual ~IView() = default;
 
    // === Lifecycle ===

    virtual void onEnter(void* context = nullptr) = 0;

    virtual void onExit() = 0;

    virtual void onResume() = 0;

    virtual void onPause() {}
 
    // === Rendering ===

    virtual void render(bool partial) = 0;

    virtual bool needsRender() const = 0;

    virtual void markDirty() = 0;

    virtual void clearDirty() = 0;

    virtual bool prefersLightRefresh() const { return false; }
 
    // === Input ===

    virtual InputResult onKey(char key) = 0;

    virtual InputResult onLongPress(char key) { (void)key; return InputResult::IGNORED; }
 
    // === Periodic ===

    virtual void onTick(uint32_t nowMs) { (void)nowMs; }
 
    // === Footer ===

    virtual const char* getFooterHint() const { return nullptr; }

    virtual void setFooterHint(const char* hint) { (void)hint; }

    virtual void setLifecycleHooks(void (*onHide)(void*), void (*onShow)(void*), void* userData) {
        (void)onHide; (void)onShow; (void)userData;
    }
 
    // === Identity ===

    virtual const char* getName() const = 0;
};

class ViewBase : public IView {
public:
    virtual ~ViewBase() = default;
 
    // Lifecycle with default implementations
    void onEnter(void* context) override {
        (void)context;
        dirty_ = true;
    }
 
    void onExit() override { }
 
    void onResume() override {
        dirty_ = true;
        if (onShow_) onShow_(lifecycleUserData_);
    }
 
    void onPause() override {
        if (onHide_) onHide_(lifecycleUserData_);
    }
 
    void setLifecycleHooks(void (*onHide)(void*), void (*onShow)(void*), void* userData) override {
        onHide_ = onHide;
        onShow_ = onShow;
        lifecycleUserData_ = userData;
    }
 
    // Dirty flag management
    bool needsRender() const override { return dirty_; }
    void markDirty() override { dirty_ = true; }
    void clearDirty() override { dirty_ = false; }
 
    // Footer override (universal). Subclasses that wire their own
    // getFooterHint() can still consult customFooter_ first.
    void setFooterHint(const char* hint) override {
        customFooter_ = hint;
        dirty_ = true;
    }
    const char* getFooterHint() const override { return customFooter_; }
 
protected:
    void setTitle(const char* title) { title_ = title; }
    const char* getTitle() const { return title_; }
 
    bool dirty_ = true;
    const char* title_ = nullptr;
    const char* customFooter_ = nullptr;
 
    void (*onHide_)(void*) = nullptr;
    void (*onShow_)(void*) = nullptr;
    void* lifecycleUserData_ = nullptr;
};
 
} // namespace cdc::ui