利用audio PreviewWidget在Scope中来播放音乐

在我们的Scope PreviewWidget，我们可以利用audio PreviewWidget来播放我们的音乐。这对一些音乐的Scope来说，非常中要。在今天的练习中，我们来利用这个它来在我们的Scope中来试听我们的音乐。

首先我们来利用我们已经做好的Scope。我们可以下载我们先前做好的Scope:

git clone https://gitcafe.com/ubuntu/scopetemplates.git

在我们的query.cpp中，我们来添加如下的项：

query.cpp

void Query::pushResult(sc::SearchReplyProxy const& reply,
                       const string renderer, int i) {
    stringstream ss;
    ss << i;
    string str = ss.str();

    auto cat = reply->register_category( "id" + str, "Template " + str ,
                                         "", sc::CategoryRenderer(renderer) );
    sc::CategorisedResult r(cat);
    r.set_uri( URI.toStdString() );
    r.set_art( images_[0].toStdString() );
    r["subtitle"] = "Subtitle " + str;
    r.set_title("Title " + str);
    r["summary"] = "Summary: " + str;
    r["fulldesc"] = "fulldesc: " + str;
    r["mascot"] = icons_[0].toStdString();
    r["emblem"] = icons_[1].toStdString();
    r["background"] = background_.toStdString();
    r["overlay-color"] = "#FF0000";

    QString likes = QString("%1 %2").arg(qstr(u8"\u261d "), "100");
    QString views = QString("%1 %2").arg(qstr(u8"   \u261f "), "99");
    std::string both = qstr("%1 %2").arg(likes,views).toStdString();
    sc::VariantBuilder builder;
    builder.add_tuple({
        {"value", Variant(both)}
    });
    builder.add_tuple({
        {"value", Variant("")}
    });
    r["attributes"] = builder.end();

    r["musicSource"] = "http://qqmp3.djwma.com/mp3/魔音神据极品私货这锯子拉的耳膜都要碎了.mp3";

    if (!reply->push(r))
        return;
}

上面的“musicSource”是我们新添加的项。我们必须指出的是，“musicSource”不是我们标准的模版中的项，那么我们怎么在我们的Preview中利用这个项呢？

preview.cpp

void Preview::run(sc::PreviewReplyProxy const& reply) {
    // Support three different column layouts
    sc::ColumnLayout layout1col(1), layout2col(2), layout3col(3);

    // We define 3 different layouts, that will be used depending on the
    // device. The shell (view) will decide which layout fits best.
    // If, for instance, we are executing in a tablet probably the view will use
    // 2 or more columns.
    // Column layout definitions are optional.
    // However, we recommend that scopes define layouts for the best visual appearance.

    // Single column layout
    layout1col.add_column( { "image", "header", "summary", "tracks" });

    // Two column layout
    layout2col.add_column( { "image" });
    layout2col.add_column( { "header", "summary", "tracks" });

    // Three cokumn layout
    layout3col.add_column( { "image" });
    layout3col.add_column( { "header", "summary", "tracks" });
    layout3col.add_column( { });

    // Register the layouts we just created
    reply->register_layout( { layout1col, layout2col, layout3col });

    // Define the header section
    sc::PreviewWidget header("header", "header");
    // It has title and a subtitle properties
    header.add_attribute_mapping("title", "title");
    header.add_attribute_mapping("subtitle", "subtitle");

    // Define the image section
    sc::PreviewWidget image("image", "image");
    // It has a single source property, mapped to the result's art property
    image.add_attribute_mapping("source", "art");

    // Define the summary section
    sc::PreviewWidget description("summary", "text");
    // It has a text property, mapped to the result's description property
    description.add_attribute_mapping("text", "description");
 　 Result result = PreviewQueryBase::result();
    PreviewWidget listen("tracks", "audio");
    {
        VariantBuilder builder;
        builder.add_tuple({
            {"title", Variant("This is the song title")},
            {"source", Variant(result["musicSource"].get_string().c_str())}
        });
        listen.add_attribute_value("tracks", builder.end());
    }

    if ( result["musicSource"].get_string().length() != 0 ) {
        qDebug() << "it is not null";
        // Push each of the sections
        reply->push( { image, header, description, listen });

    } else {
        // Push each of the sections
        reply->push( { image, header, description });
    }

}

在这里，我们可以看到：

  　Result result = PreviewQueryBase::result();
    PreviewWidget listen("tracks", "audio");
    {
        VariantBuilder builder;
        builder.add_tuple({
            {"title", Variant("This is the song title")},
            {"source", Variant(result["musicSource"].get_string().c_str())}
        });
        listen.add_attribute_value("tracks", builder.end());
    }

    if ( result["musicSource"].get_string().length() != 0 ) {
        qDebug() << "it is not null";
        // Push each of the sections
        reply->push( { image, header, description, listen });

    } else {
        // Push each of the sections
        reply->push( { image, header, description });
    }

我们可以通过“result()”的方法来得到result。我们同时创建了一个叫做listen的PreviewWidget。我们利用他来创建我们所需要的项。

运行我们的Scope:

我们可以点击上面的按钮来播放我们的音乐来试听！

整个项目的源码在：git clone https://gitcafe.com/ubuntu/scopetemplates_audio.git