HarmonyOS Next开发----使用XComponent自定义绘制

XComponent组件作为一种绘制组件，通常用于满足用户复杂的自定义绘制需求，其主要有两种类型"surface和component。对于surface类型可以将相关数据传入XComponent单独拥有的NativeWindow来渲染画面。

由于上层UI是采用arkTS开发，那么想要使用XComponent的话，就需要一个桥接和native层交互，类似Android的JNI,鸿蒙应用可以使用napi接口来处理js和native层的交互。

1. 编写CMAKELists.txt文件

# the minimum version of CMake.
cmake_minimum_required(VERSION 3.4.1)
project(XComponent) #项目名称

set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})
#头文件查找路径
include_directories(
    ${NATIVERENDER_ROOT_PATH}
    ${NATIVERENDER_ROOT_PATH}/include
)
# 编译目标so动态库
add_library(nativerender SHARED
    samples/minute_view.cpp
    plugin/plugin_manager.cpp
    common/HuMarketMinuteData.cpp
    common/MinuteItem.cpp
    napi_init.cpp
)
# 查找需要的公共库
find_library(
    # Sets the name of the path variable.
    hilog-lib
    # Specifies the name of the NDK library that
    # you want CMake to locate.
    hilog_ndk.z
)
#编译so所需要的依赖
target_link_libraries(nativerender PUBLIC
    libc++.a
    ${hilog-lib}
    libace_napi.z.so
    libace_ndk.z.so
    libnative_window.so
    libnative_drawing.so
)

2. Napi模块注册

#include <hilog/log.h>
#include "plugin/plugin_manager.h"
#include "common/log_common.h"

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports)
{
    OH_LOG_Print(LOG_APP, LOG_INFO, LOG_PRINT_DOMAIN, "Init", "Init begins");
    if ((nullptr == env) || (nullptr == exports)) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, LOG_PRINT_DOMAIN, "Init", "env or exports is null");
        return nullptr;
    }

    PluginManager::GetInstance()->Export(env, exports);
    return exports;
}
EXTERN_C_END

static napi_module nativerenderModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "nativerender",
    .nm_priv = ((void *)0),
    .reserved = { 0 }
};

extern "C" __attribute__((constructor)) void RegisterModule(void)
{
    napi_module_register(&nativerenderModule);
}

定义napi_module信息，里面包含模块名称(和arkts侧使用时的libraryname要保持一致)，加载模块时的回调函数即Init()。然后注册so模块napi_module_register(&nativerenderModule), 接口Init()函数会收到回调，在Init()有两个参数：

• env: napi上下文环境；
• exports: 用于挂载native函数将其导出，会通过js引擎绑定到js层的一个js对象；

3.解析XComponent组件的NativeXComponent实例

 if ((env == nullptr) || (exports == nullptr)) {
        DRAWING_LOGE("Export: env or exports is null");
        return;
    }

    napi_value exportInstance = nullptr;
     // 用来解析出被wrap了NativeXComponent指针的属性
    if (napi_get_named_property(env, exports, OH_NATIVE_XCOMPONENT_OBJ, &exportInstance) != napi_ok) {
        DRAWING_LOGE("Export: napi_get_named_property fail");
        return;
    }

    OH_NativeXComponent *nativeXComponent = nullptr;
    // 通过napi_unwrap接口，解析出NativeXComponent的实例指针
    if (napi_unwrap(env, exportInstance, reinterpret_cast<void **>(&nativeXComponent)) != napi_ok) {
        DRAWING_LOGE("Export: napi_unwrap fail");
        return;
    }

    char idStr[OH_XCOMPONENT_ID_LEN_MAX + 1] = {'\0'};
    uint64_t idSize = OH_XCOMPONENT_ID_LEN_MAX + 1;
    if (OH_NativeXComponent_GetXComponentId(nativeXComponent, idStr, &idSize) != OH_NATIVEXCOMPONENT_RESULT_SUCCESS) {
        DRAWING_LOGE("Export: OH_NativeXComponent_GetXComponentId fail");
        return;
    }

4.注册XComponent事件回调

void MinuteView::RegisterCallback(OH_NativeXComponent *nativeXComponent) {
    DRAWING_LOGI("register callback");
    renderCallback_.OnSurfaceCreated = OnSurfaceCreatedCB;
    renderCallback_.OnSurfaceDestroyed = OnSurfaceDestroyedCB;
    renderCallback_.DispatchTouchEvent = nullptr;
    renderCallback_.OnSurfaceChanged = OnSurfaceChanged;
    // 注册XComponent事件回调
    OH_NativeXComponent_RegisterCallback(nativeXComponent, &renderCallback_);
}

在事件回调中可以获取组件的宽高信息：

tatic void OnSurfaceCreatedCB(OH_NativeXComponent *component, void *window) {
    DRAWING_LOGI("OnSurfaceCreatedCB");
    if ((component == nullptr) || (window == nullptr)) {
        DRAWING_LOGE("OnSurfaceCreatedCB: component or window is null");
        return;
    }
    char idStr[OH_XCOMPONENT_ID_LEN_MAX + 1] = {'\0'};
    uint64_t idSize = OH_XCOMPONENT_ID_LEN_MAX + 1;
    if (OH_NativeXComponent_GetXComponentId(component, idStr, &idSize) != OH_NATIVEXCOMPONENT_RESULT_SUCCESS) {
        DRAWING_LOGE("OnSurfaceCreatedCB: Unable to get XComponent id");
        return;
    }
    std::string id(idStr);
    auto render = MinuteView::GetInstance(id);
    OHNativeWindow *nativeWindow = static_cast<OHNativeWindow *>(window);
    render->SetNativeWindow(nativeWindow);

    uint64_t width;
    uint64_t height;
    int32_t xSize = OH_NativeXComponent_GetXComponentSize(component, window, &width, &height);
    if ((xSize == OH_NATIVEXCOMPONENT_RESULT_SUCCESS) && (render != nullptr)) {
        render->SetHeight(height);
        render->SetWidth(width);
    }
}

5.导出Native函数

void MinuteView::Export(napi_env env, napi_value exports) {
    if ((env == nullptr) || (exports == nullptr)) {
        DRAWING_LOGE("Export: env or exports is null");
        return;
    }
    napi_property_descriptor desc[] = {
        {"draw", nullptr, MinuteView::NapiDraw, nullptr, nullptr, nullptr, napi_default, nullptr}};
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    if (napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc) != napi_ok) {
        DRAWING_LOGE("Export: napi_define_properties failed");
    }
}

6.在NapiDraw中绘制分时图

• 1.读取arkts侧透传过来的数据

vector<HuMarketMinuteData *> myVector;

    size_t argc = 3;
    napi_value args[3] = {nullptr};
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);

    napi_value vec = args[0];    // vector
    napi_value vecNum = args[1]; // length

    uint32_t vecCNum = 0;
    napi_get_value_uint32(env, vecNum, &vecCNum);

    for (uint32_t i = 0; i < vecCNum; i++) {
        napi_value vecData;
        napi_get_element(env, vec, i, &vecData);
        HuMarketMinuteData *minuteData = new HuMarketMinuteData(&env, vecData);

        myVector.push_back(minuteData);
    }

#include "HuMarketMinuteData.h"
#include "common/MinuteItem.h"
#include "napi/native_api.h"
HuMarketMinuteData::HuMarketMinuteData(napi_env *env, napi_value value) {
    napi_value api_date, api_isDateChanged, api_yclosePrice, api_minuteItems;
    napi_get_named_property(*env, value, "date", &api_date);
    napi_get_named_property(*env, value, "isDateChanged", &api_isDateChanged);
    napi_get_named_property(*env, value, "yClosePrice", &api_yclosePrice);
    napi_get_named_property(*env, value, "minuteList", &api_minuteItems);

    uint32_t *uint32_date;
    napi_get_value_uint32(*env, api_date, uint32_date);
    date = int(*uint32_date);

    napi_get_value_double(*env, api_yclosePrice, &yClosePrice);

    uint32_t length;
    napi_get_array_length(*env, api_minuteItems, &length);
    for (uint32_t i = 0; i < length; i++) {
        napi_value api_minuteItem;
        napi_get_element(*env, api_minuteItems, i, &api_minuteItem);
        MinuteItem *minuteItem = new MinuteItem(env, api_minuteItem);
        minuteList.push_back(minuteItem);
    }
}
HuMarketMinuteData::~HuMarketMinuteData() {
    for (MinuteItem *item : minuteList) {
        delete item;
        item = nullptr;
    }
}

• 2.绘制分时图

void MinuteView::Drawing2(vector<HuMarketMinuteData *>& minuteDatas) {
    if (nativeWindow_ == nullptr) {
        DRAWING_LOGE("nativeWindow_ is nullptr");
        return;
    }

    int ret = OH_NativeWindow_NativeWindowRequestBuffer(nativeWindow_, &buffer_, &fenceFd_);
    DRAWING_LOGI("request buffer ret = %{public}d", ret);
    bufferHandle_ = OH_NativeWindow_GetBufferHandleFromNative(buffer_);
    mappedAddr_ = static_cast<uint32_t *>(
        mmap(bufferHandle_->virAddr, bufferHandle_->size, PROT_READ | PROT_WRITE, MAP_SHARED, bufferHandle_->fd, 0));
    if (mappedAddr_ == MAP_FAILED) {
        DRAWING_LOGE("mmap failed");
    }
    
    // 创建一个bitmap对象
    cBitmap_ = OH_Drawing_BitmapCreate();
    // 定义bitmap的像素格式
    OH_Drawing_BitmapFormat cFormat{COLOR_FORMAT_RGBA_8888, ALPHA_FORMAT_OPAQUE};
    // 构造对应格式的bitmap，width的值必须为 bufferHandle->stride / 4
    OH_Drawing_BitmapBuild(cBitmap_, width_, height_, &cFormat);

    // 创建一个canvas对象
    cCanvas_ = OH_Drawing_CanvasCreate();
    // 将画布与bitmap绑定，画布画的内容会输出到绑定的bitmap内存中
    OH_Drawing_CanvasBind(cCanvas_, cBitmap_);
    // 清除画布内容
    OH_Drawing_CanvasClear(cCanvas_, OH_Drawing_ColorSetArgb(0xFF, 0xFF, 0xFF, 0xFF));
    
    float padding = 30, with = width_, height = height_ / 2;
    float ltX = padding, ltY = 1, rtX = with - padding,rtY = 1,lbX = padding,lbY = height - 1,rbX = with - padding,rbY = height - 1;
    
    // 创建一个path对象
    cPath_ = OH_Drawing_PathCreate();
    // 指定path的起始位置
    OH_Drawing_PathMoveTo(cPath_, ltX, ltY);
    // 用直线连接到目标点
    OH_Drawing_PathLineTo(cPath_, rtX, rtY);
    OH_Drawing_PathLineTo(cPath_, rbX, rbY);
    OH_Drawing_PathLineTo(cPath_, lbX, lbY);
    // 闭合形状，path绘制完毕
    OH_Drawing_PathClose(cPath_);

    OH_Drawing_PathMoveTo(cPath_, padding, height / 2);
    OH_Drawing_PathLineTo(cPath_, with - padding, height / 2);

    OH_Drawing_PathMoveTo(cPath_, with / 2, 1);
    OH_Drawing_PathLineTo(cPath_, with / 2, height - 1);

    // 创建一个画笔Pen对象，Pen对象用于形状的边框线绘制
    cPen_ = OH_Drawing_PenCreate();
    OH_Drawing_PenSetAntiAlias(cPen_, true);
    OH_Drawing_PenSetColor(cPen_, OH_Drawing_ColorSetArgb(0xFF, 0xE6, 0xE6, 0xE6));
    OH_Drawing_PenSetWidth(cPen_, 2.0);
    OH_Drawing_PenSetJoin(cPen_, LINE_ROUND_JOIN);
    // 将Pen画笔设置到canvas中
    OH_Drawing_CanvasAttachPen(cCanvas_, cPen_);

    OH_Drawing_CanvasDrawPath(cCanvas_, cPath_);


    double minPrice, maxPrice;
    computeMaxMin(minuteDatas, &minPrice, &maxPrice);
    OH_Drawing_Path *pricePath_ = OH_Drawing_PathCreate();
    OH_Drawing_Path *avgPath_ = OH_Drawing_PathCreate();
    // 指定path的起始位置
    HuMarketMinuteData *minuteData = minuteDatas[0];
    // 单位长度
    float unitHeight = height / (maxPrice - minPrice);
    float itemWidth = (with - 2 * padding) / (240 * minuteDatas.size());
    float pointX = padding;
    float pointY = 0;
    float avg_pointX = padding;
    float avg_pointY = 0;
    bool isFirst = true;
    float yClosePrice = 0;

    for (int i = 0; i < minuteDatas.size(); i++) {
        HuMarketMinuteData *minuteData = minuteDatas[i];
        if (i == 0) {
            yClosePrice = minuteData->yClosePrice;
        }
        if (minuteData != nullptr) {
            for (int j = 0; j < minuteData->minuteList.size(); j++) {
                MinuteItem *minuteItem = minuteData->minuteList[j];
                if (minuteItem != nullptr) {
                    pointY = (maxPrice - minuteItem->nowPrice) * unitHeight;
                    avg_pointY = (maxPrice - minuteItem->avgPrice) * unitHeight;
                    if (isFirst) {
                        isFirst = false;
                        OH_Drawing_PathMoveTo(pricePath_, pointX, pointY);
                        OH_Drawing_PathMoveTo(avgPath_, avg_pointX, avg_pointY);
                    } else {
                        OH_Drawing_PathLineTo(pricePath_, pointX, pointY);
                        OH_Drawing_PathLineTo(avgPath_, avg_pointX, avg_pointY);
                    }
                    pointX += itemWidth;
                    avg_pointX += itemWidth;
                }
            }
        }
    }

    // 创建一个画笔Pen对象，Pen对象用于形状的边框线绘制
    cPen_ = OH_Drawing_PenCreate();
    OH_Drawing_PenSetAntiAlias(cPen_, true);
    OH_Drawing_PenSetColor(cPen_, OH_Drawing_ColorSetArgb(0xFF, 0x22, 0x77, 0xcc));
    OH_Drawing_PenSetWidth(cPen_, 5.0);
    OH_Drawing_PenSetJoin(cPen_, LINE_ROUND_JOIN);
    // 将Pen画笔设置到canvas中
    OH_Drawing_CanvasAttachPen(cCanvas_, cPen_);
    // 在画布上画Price
    OH_Drawing_CanvasDrawPath(cCanvas_, pricePath_);
    OH_Drawing_PenSetColor(cPen_, OH_Drawing_ColorSetArgb(0xFF, 0xFF, 0x9D, 0x03));
    OH_Drawing_CanvasAttachPen(cCanvas_, cPen_);
    OH_Drawing_CanvasDrawPath(cCanvas_, avgPath_);
    OH_Drawing_PathLineTo(pricePath_, pointX, height);
    OH_Drawing_PathLineTo(pricePath_, padding, height);
    OH_Drawing_PathClose(pricePath_);
    OH_Drawing_CanvasDrawShadow(cCanvas_, pricePath_, {5, 5, 5}, {15, 15, 15}, 30,
                                OH_Drawing_ColorSetArgb(0x00, 0xFF, 0xff, 0xff),
                                OH_Drawing_ColorSetArgb(0x33, 0x22, 0x77, 0xcc), SHADOW_FLAGS_TRANSPARENT_OCCLUDER);
    // 选择从左到右/左对齐等排版属性
    OH_Drawing_TypographyStyle *typoStyle = OH_Drawing_CreateTypographyStyle();
    OH_Drawing_SetTypographyTextDirection(typoStyle, TEXT_DIRECTION_LTR);
    OH_Drawing_SetTypographyTextAlign(typoStyle, TEXT_ALIGN_LEFT);
    // 设置文字颜色，例如黑色
    OH_Drawing_TextStyle *txtStyle = OH_Drawing_CreateTextStyle();
    OH_Drawing_SetTextStyleColor(txtStyle, OH_Drawing_ColorSetArgb(0xFF, 0xFF, 0x9D, 0x03));
    // 设置文字大小、字重等属性
    double fontSize = width_ / 15;
    OH_Drawing_SetTextStyleFontSize(txtStyle, fontSize);
    OH_Drawing_SetTextStyleFontWeight(txtStyle, FONT_WEIGHT_400);
    OH_Drawing_SetTextStyleBaseLine(txtStyle, TEXT_BASELINE_ALPHABETIC);
    OH_Drawing_SetTextStyleFontHeight(txtStyle, 1);
    // 如果需要多次测量，建议fontCollection作为全局变量使用，可以显著减少内存占用

    OH_Drawing_FontCollection *fontCollection = OH_Drawing_CreateSharedFontCollection();
    // 注册自定义字体
    const char *fontFamily = "myFamilyName"; // myFamilyName为自定义字体的family name
    const char *fontPath = "/data/storage/el2/base/haps/entry/files/myFontFile.ttf"; // 设置自定义字体所在的沙箱路径
    OH_Drawing_RegisterFont(fontCollection, fontFamily, fontPath);
    // 设置系统字体类型
    const char *systemFontFamilies[] = {"Roboto"};
    OH_Drawing_SetTextStyleFontFamilies(txtStyle, 1, systemFontFamilies);
    OH_Drawing_SetTextStyleFontStyle(txtStyle, FONT_STYLE_NORMAL);
    OH_Drawing_SetTextStyleLocale(txtStyle, "en");
    // 设置自定义字体类型
    auto txtStyle2 = OH_Drawing_CreateTextStyle();
    OH_Drawing_SetTextStyleFontSize(txtStyle2, fontSize);
    const char *myFontFamilies[] = {"myFamilyName"}; // 如果已经注册自定义字体，填入自定义字体的family
                                                     // name使用自定义字体
    OH_Drawing_SetTextStyleFontFamilies(txtStyle2, 1, myFontFamilies);
    OH_Drawing_TypographyCreate *handler = OH_Drawing_CreateTypographyHandler(typoStyle, fontCollection);
    OH_Drawing_TypographyHandlerPushTextStyle(handler, txtStyle);
    OH_Drawing_TypographyHandlerPushTextStyle(handler, txtStyle2);
    // 设置文字内容
    const char *text = doubleToStringWithPrecision(yClosePrice, 2).c_str();
    OH_Drawing_TypographyHandlerAddText(handler, text);
    OH_Drawing_TypographyHandlerPopTextStyle(handler);
    OH_Drawing_Typography *typography = OH_Drawing_CreateTypography(handler);
    // 设置页面最大宽度
    double maxWidth = width_;
    OH_Drawing_TypographyLayout(typography, maxWidth);
    // 设置文本在画布上绘制的起始位置
    double position[2] = {100, height / 2.0};
    // 将文本绘制到画布上
    OH_Drawing_TypographyPaint(typography, cCanvas_, position[0], position[1]);
    
    void *bitmapAddr = OH_Drawing_BitmapGetPixels(cBitmap_);
    uint32_t *value = static_cast<uint32_t *>(bitmapAddr);

    uint32_t *pixel = static_cast<uint32_t *>(mappedAddr_);
    if (pixel == nullptr) {
        DRAWING_LOGE("pixel is null");
        return;
    }
    if (value == nullptr) {
        DRAWING_LOGE("value is null");
        return;
    }
    for (uint32_t x = 0; x < width_; x++) {
        for (uint32_t y = 0; y < height_; y++) {
            *pixel++ = *value++;
        }
    }

    Region region{nullptr, 0};
    OH_NativeWindow_NativeWindowFlushBuffer(nativeWindow_, buffer_, fenceFd_, region);
    int result = munmap(mappedAddr_, bufferHandle_->size);
    if (result == -1) {
        DRAWING_LOGE("munmap failed!");
    }
}

绘制流程：

• 向OHNativeWindow申请一块buffer, 并获取这块buffer的handle，然后映射内存；
• 创建画布Canvas, 将bitmap和画布绑定；
• 使用Canvas相关api绘制内容；
• 将bitmap转换成像素数据，并通过之前映射的buffer句柄，将bitmap数据写到buffer中；
• 将内容放回到Buffer队列，在下次Vsync信号就会将buffer中的内容绘制到屏幕上；
• 取消映射内存；

7.ArkTS侧使用XComponent

• 添加so依赖

  "devDependencies": {
   "@types/libnativerender.so": "file:./src/main/cpp/types/libnativerender"
 }

• 定义native接口

export default interface XComponentContext {
 draw(minuteData: UPMarketMinuteData[], length: number): void;
};

• 使用XComponent并获取XComponentContext, 通过它可以调用native层函数

      XComponent({
         id: 'xcomponentId',
         type: 'surface',
         libraryname: 'nativerender'
       })
         .onLoad((xComponentContext) => {
           if (xComponentContext) {
             this.xComponentContext = xComponentContext as XComponentContext;
           }
         })
         .width('100%')
         .height(600)
         .backgroundColor(Color.Gray)

• 调用native函数绘制分时图

    this.monitor.subscribeRTMinuteData(this.TAG_REQUEST_MINUTE, param, (rsp) => {
     if (rsp.isSuccessful() && rsp.result != null && rsp.result.length > 0 && this.xComponentContext) {
       this.xComponentContext.draw(rsp.result!, rsp.result.length)
     }
   })