dropdown.cpp

/**
 * Dropdown Component
 * 
 * 下拉菜单组件示例
 * 演示展开/收起、选项列表、鼠标交互和键盘导航
 */

#include "runtime_api.h"
#include <cmath>
#include <cstdio>
#include <cstring>

class DropdownComponent : public BitHCI::IComponent {
private:
    // 运行时接口
    BitHCI::IRenderer* renderer = nullptr;
    BitHCI::IInput* input = nullptr;
    BitHCI::IWindow* window = nullptr;
    
    // 鼠标状态
    float mouseX = 0.0f;
    float mouseY = 0.0f;
    bool mousePressed = false;
    bool mouseWasPressed = false;
    
    // 动画参数
    float time = 0.0f;
    bool paused = false;
    
    // Dropdown 数据结构
    struct Dropdown {
        float x, y;                  // 位置
        float width, height;         // 尺寸
        
        const char* options[10];     // 选项列表
        int optionCount;             // 选项数量
        int selectedIndex;           // 当前选中的索引
        int hoveredIndex;            // 鼠标悬停的索引
        
        bool isExpanded;             // 是否展开
        float expandProgress;        // 展开进度（0.0 - 1.0）
        
        const char* label;           // 标签文本
        
        // 样式
        float bgColor[4];
        float hoverColor[4];
        float selectedColor[4];
        float textColor[4];
        float textSize;
    };
    
    // 预定义的下拉菜单
    Dropdown dropdowns[3];
    int dropdownCount;
    
    // 常量
    static constexpr float EXPAND_SPEED = 8.0f;  // 展开速度
    static constexpr float OPTION_HEIGHT = 30.0f; // 选项高度
    static constexpr float ARROW_SIZE = 8.0f;    // 箭头大小
    
public:
    void onInit(BitHCI::IWindow* win, 
                BitHCI::IRenderer* ren, 
                BitHCI::IInput* inp,
                BitHCI::IResourceManager* resources) override {
        window = win;
        renderer = ren;
        input = inp;
        time = 0.0f;
        paused = false;
        
        // 设置清屏颜色
        renderer->setClearColor(0.08f, 0.08f, 0.12f, 1.0f);
        
        // 初始化下拉菜单
        dropdownCount = 0;
        
        // 1. 水果选择器
        dropdowns[dropdownCount] = {
            -250.0f, -80.0f, 180.0f, 35.0f,
            {"APPLE", "BANANA", "ORANGE", "GRAPE", "PEACH"},
            5, 0, -1,
            false, 0.0f,
            "SELECT FRUIT:",
            {0.2f, 0.25f, 0.35f, 1.0f},  // 背景色
            {0.3f, 0.4f, 0.6f, 1.0f},    // 悬停色
            {0.3f, 0.5f, 0.4f, 1.0f},    // 选中色
            {1.0f, 1.0f, 1.0f, 1.0f},    // 文字色
            12.0f
        };
        dropdownCount++;
        
        // 2. 颜色选择器
        dropdowns[dropdownCount] = {
            -30.0f, -80.0f, 180.0f, 35.0f,
            {"RED", "GREEN", "BLUE", "YELLOW", "CYAN", "MAGENTA"},
            6, 2, -1,
            false, 0.0f,
            "SELECT COLOR:",
            {0.25f, 0.2f, 0.3f, 1.0f},
            {0.4f, 0.3f, 0.5f, 1.0f},
            {0.5f, 0.3f, 0.4f, 1.0f},
            {1.0f, 1.0f, 1.0f, 1.0f},
            12.0f
        };
        dropdownCount++;
        
        // 3. 大小选择器
        dropdowns[dropdownCount] = {
            190.0f, -80.0f, 180.0f, 35.0f,
            {"SMALL", "MEDIUM", "LARGE", "XLARGE"},
            4, 1, -1,
            false, 0.0f,
            "SELECT SIZE:",
            {0.2f, 0.3f, 0.25f, 1.0f},
            {0.3f, 0.5f, 0.4f, 1.0f},
            {0.4f, 0.6f, 0.3f, 1.0f},
            {1.0f, 1.0f, 1.0f, 1.0f},
            12.0f
        };
        dropdownCount++;
    }
    
    void onUpdate(float deltaTime) override {
        // ESC 键退出
        if (input->isKeyJustPressed(27)) {
            window->close();
        }
        
        // 空格键暂停/继续
        if (input->isKeyJustPressed(32)) {
            paused = !paused;
        }
        
        // R 键重置
        if (input->isKeyJustPressed('R')) {
            time = 0.0f;
            paused = false;
            for (int i = 0; i < dropdownCount; i++) {
                dropdowns[i].isExpanded = false;
                dropdowns[i].expandProgress = 0.0f;
                dropdowns[i].selectedIndex = 0;
                dropdowns[i].hoveredIndex = -1;
            }
        }
        
        // 获取鼠标状态（已经是渲染坐标系，中心为原点）
        input->getMousePosition(mouseX, mouseY);
        
        mouseWasPressed = mousePressed;
        mousePressed = input->isMouseButtonPressed(0);
        
        // 更新时间
        if (!paused) {
            time += deltaTime;
            
            // 处理键盘导航
            handleKeyboardNavigation();
            
            // 更新每个 dropdown
            for (int i = 0; i < dropdownCount; i++) {
                updateDropdown(dropdowns[i], deltaTime);
            }
            
            // 处理鼠标点击
            if (mousePressed && !mouseWasPressed) {
                handleMouseClick();
            }
        }
    }
    
    void onRender() override {
        // 绘制标题
        float titleColor[4] = {1.0f, 1.0f, 1.0f, 1.0f};
        renderer->drawText("DROPDOWN MENU DEMO", -130.0f, -180.0f, titleColor, 20.0f);
        
        // 绘制提示信息
        float hintColor[4] = {0.5f, 0.5f, 0.5f, 1.0f};
        renderer->drawText("CLICK TO EXPAND  USE ARROW KEYS TO NAVIGATE", -200.0f, -155.0f, hintColor, 10.0f);
        
        // 绘制所有 dropdown
        for (int i = 0; i < dropdownCount; i++) {
            drawDropdown(dropdowns[i]);
        }
        
        // 绘制选择结果
        char result[256];
        sprintf_s(result, sizeof(result), "SELECTIONS: %s | %s | %s", 
                 dropdowns[0].options[dropdowns[0].selectedIndex],
                 dropdowns[1].options[dropdowns[1].selectedIndex],
                 dropdowns[2].options[dropdowns[2].selectedIndex]);
        float resultColor[4] = {0.8f, 0.9f, 1.0f, 1.0f};
        renderer->drawText(result, -200.0f, 160.0f, resultColor, 14.0f);
        
        // 绘制底部提示
        renderer->drawText("[SPACE] PAUSE  [R] RESET  [ESC] EXIT", -170.0f, 190.0f, hintColor, 10.0f);
        
        // 绘制统计信息
        char stats[128];
        sprintf_s(stats, sizeof(stats), "TIME: %.1FS  DROPDOWNS: %d", time, dropdownCount);
        float statsColor[4] = {0.5f, 0.5f, 0.5f, 1.0f};
        renderer->drawText(stats, -280.0f, -200.0f, statsColor, 10.0f);
        
        // 暂停指示
        if (paused) {
            float pauseColor[4] = {1.0f, 1.0f, 0.0f, 1.0f};
            renderer->drawText("[PAUSED]", 200.0f, -200.0f, pauseColor, 12.0f);
        }
    }
    
    void onDestroy() override {
        // 清理资源
    }
    
private:
    // 更新 dropdown 状态
    void updateDropdown(Dropdown& dropdown, float deltaTime) {
        // 更新展开进度
        float targetProgress = dropdown.isExpanded ? 1.0f : 0.0f;
        
        if (dropdown.expandProgress < targetProgress) {
            dropdown.expandProgress += EXPAND_SPEED * deltaTime;
            if (dropdown.expandProgress > targetProgress) 
                dropdown.expandProgress = targetProgress;
        } else if (dropdown.expandProgress > targetProgress) {
            dropdown.expandProgress -= EXPAND_SPEED * deltaTime;
            if (dropdown.expandProgress < targetProgress) 
                dropdown.expandProgress = targetProgress;
        }
        
        // 更新悬停索引
        if (dropdown.isExpanded) {
            dropdown.hoveredIndex = getHoveredOptionIndex(dropdown);
        } else {
            dropdown.hoveredIndex = -1;
        }
    }
    
    // 获取鼠标悬停的选项索引
    int getHoveredOptionIndex(const Dropdown& dropdown) {
        float listY = dropdown.y + dropdown.height;
        float listHeight = dropdown.optionCount * OPTION_HEIGHT * dropdown.expandProgress;
        
        if (mouseX < dropdown.x || mouseX > dropdown.x + dropdown.width) return -1;
        if (mouseY < listY || mouseY > listY + listHeight) return -1;
        
        int index = static_cast<int>((mouseY - listY) / OPTION_HEIGHT);
        if (index >= 0 && index < dropdown.optionCount) {
            return index;
        }
        return -1;
    }
    
    // 处理鼠标点击
    void handleMouseClick() {
        // 检查是否点击了任何 dropdown 的按钮
        for (int i = 0; i < dropdownCount; i++) {
            if (isMouseInRect(dropdowns[i].x, dropdowns[i].y, 
                             dropdowns[i].width, dropdowns[i].height)) {
                // 点击按钮，切换展开状态
                dropdowns[i].isExpanded = !dropdowns[i].isExpanded;
                
                // 关闭其他 dropdown
                for (int j = 0; j < dropdownCount; j++) {
                    if (j != i) dropdowns[j].isExpanded = false;
                }
                return;
            }
            
            // 检查是否点击了选项
            if (dropdowns[i].isExpanded && dropdowns[i].hoveredIndex != -1) {
                dropdowns[i].selectedIndex = dropdowns[i].hoveredIndex;
                dropdowns[i].isExpanded = false;
                return;
            }
        }
        
        // 点击了空白区域，关闭所有 dropdown
        for (int i = 0; i < dropdownCount; i++) {
            dropdowns[i].isExpanded = false;
        }
    }
    
    // 处理键盘导航
    void handleKeyboardNavigation() {
        // 找到展开的 dropdown
        for (int i = 0; i < dropdownCount; i++) {
            if (dropdowns[i].isExpanded) {
                // 上箭头
                if (input->isKeyJustPressed(38)) {
                    if (dropdowns[i].selectedIndex > 0) {
                        dropdowns[i].selectedIndex--;
                    }
                }
                // 下箭头
                if (input->isKeyJustPressed(40)) {
                    if (dropdowns[i].selectedIndex < dropdowns[i].optionCount - 1) {
                        dropdowns[i].selectedIndex++;
                    }
                }
                // 回车键确认并关闭
                if (input->isKeyJustPressed(13)) {
                    dropdowns[i].isExpanded = false;
                }
                break;
            }
        }
    }
    
    // 检查鼠标是否在矩形内
    bool isMouseInRect(float x, float y, float w, float h) {
        return mouseX >= x && mouseX <= x + w &&
               mouseY >= y && mouseY <= y + h;
    }
    
    // 绘制 dropdown
    void drawDropdown(const Dropdown& dropdown) {
        // 绘制标签
        renderer->drawText(dropdown.label, dropdown.x, dropdown.y - 22.0f, 
                          dropdown.textColor, 11.0f);
        
        // 绘制主按钮
        drawDropdownButton(dropdown);
        
        // 绘制选项列表（如果展开）
        if (dropdown.expandProgress > 0.01f) {
            drawDropdownList(dropdown);
        }
    }
    
    // 绘制 dropdown 按钮
    void drawDropdownButton(const Dropdown& dropdown) {
        // 背景
        bool isHovered = isMouseInRect(dropdown.x, dropdown.y, 
                                       dropdown.width, dropdown.height);
        float bgColor[4];
        if (isHovered) {
            bgColor[0] = dropdown.hoverColor[0];
            bgColor[1] = dropdown.hoverColor[1];
            bgColor[2] = dropdown.hoverColor[2];
            bgColor[3] = dropdown.hoverColor[3];
        } else {
            bgColor[0] = dropdown.bgColor[0];
            bgColor[1] = dropdown.bgColor[1];
            bgColor[2] = dropdown.bgColor[2];
            bgColor[3] = dropdown.bgColor[3];
        }
        
        renderer->drawRectangle(dropdown.x, dropdown.y, 
                               dropdown.width, dropdown.height, bgColor);
        
        // 边框
        float borderColor[4] = {0.5f, 0.5f, 0.6f, 1.0f};
        drawBorder(dropdown.x, dropdown.y, dropdown.width, dropdown.height, 2.0f, borderColor);
        
        // 当前选中的文本
        const char* text = dropdown.options[dropdown.selectedIndex];
        renderer->drawText(text, dropdown.x + 10.0f, dropdown.y + 12.0f,
                          dropdown.textColor, dropdown.textSize);
        
        // 下拉箭头
        drawArrow(dropdown.x + dropdown.width - 20.0f, 
                 dropdown.y + dropdown.height / 2,
                 dropdown.isExpanded ? -1 : 1,
                 dropdown.textColor);
    }
    
    // 绘制选项列表
    void drawDropdownList(const Dropdown& dropdown) {
        float listY = dropdown.y + dropdown.height;
        float visibleHeight = dropdown.optionCount * OPTION_HEIGHT * dropdown.expandProgress;
        
        // 背景（整个列表）
        float listBgColor[4] = {0.15f, 0.15f, 0.2f, 0.95f};
        renderer->drawRectangle(dropdown.x, listY, 
                               dropdown.width, visibleHeight, listBgColor);
        
        // 边框
        float borderColor[4] = {0.5f, 0.5f, 0.6f, 1.0f};
        drawBorder(dropdown.x, listY, dropdown.width, visibleHeight, 2.0f, borderColor);
        
        // 绘制每个可见的选项
        int visibleCount = static_cast<int>(dropdown.optionCount * dropdown.expandProgress);
        for (int i = 0; i < visibleCount && i < dropdown.optionCount; i++) {
            float optionY = listY + i * OPTION_HEIGHT;
            
            // 选项背景
            bool isSelected = (i == dropdown.selectedIndex);
            bool isHovered = (i == dropdown.hoveredIndex);
            
            if (isSelected) {
                renderer->drawRectangle(dropdown.x, optionY, 
                                       dropdown.width, OPTION_HEIGHT, 
                                       dropdown.selectedColor);
            } else if (isHovered) {
                renderer->drawRectangle(dropdown.x, optionY, 
                                       dropdown.width, OPTION_HEIGHT, 
                                       dropdown.hoverColor);
            }
            
            // 选项文本
            float textColor[4];
            if (isSelected || isHovered) {
                textColor[0] = 1.0f;
                textColor[1] = 1.0f;
                textColor[2] = 1.0f;
                textColor[3] = 1.0f;
            } else {
                textColor[0] = 0.8f;
                textColor[1] = 0.8f;
                textColor[2] = 0.8f;
                textColor[3] = 1.0f;
            }
            
            renderer->drawText(dropdown.options[i], 
                             dropdown.x + 10.0f, optionY + 10.0f,
                             textColor, dropdown.textSize);
            
            // 选中标记
            if (isSelected) {
                float checkColor[4] = {0.3f, 1.0f, 0.3f, 1.0f};
                renderer->drawText("V", dropdown.x + dropdown.width - 20.0f, 
                                 optionY + 10.0f, checkColor, dropdown.textSize);
            }
        }
    }
    
    // 绘制边框
    void drawBorder(float x, float y, float w, float h, float thickness, const float* color) {
        renderer->drawRectangle(x, y, w, thickness, color);  // 上
        renderer->drawRectangle(x, y + h - thickness, w, thickness, color);  // 下
        renderer->drawRectangle(x, y, thickness, h, color);  // 左
        renderer->drawRectangle(x + w - thickness, y, thickness, h, color);  // 右
    }
    
    // 绘制箭头（direction: 1=下, -1=上）
    void drawArrow(float x, float y, int direction, const float* color) {
        float size = ARROW_SIZE;
        
        if (direction == 1) {
            // 下箭头（▼）
            renderer->drawLine(x - size, y - size/2, x, y + size/2, color, 2.0f);
            renderer->drawLine(x, y + size/2, x + size, y - size/2, color, 2.0f);
        } else {
            // 上箭头（▲）
            renderer->drawLine(x - size, y + size/2, x, y - size/2, color, 2.0f);
            renderer->drawLine(x, y - size/2, x + size, y + size/2, color, 2.0f);
        }
    }
};

// 导出组件工厂函数
extern "C" {
    __declspec(dllexport) BitHCI::IComponent* createComponent() {
        return new DropdownComponent();
    }
}