使用Picasso和Image Getter

Question

我正在构建一个聊天应用程序,我试图将图像附加到EditText,通过使用Picasso从URL获取图像和附加和ImageGetter将图像附加到EditText.但是,我在下面实现的内容不起作用,因为在使用应用程序时附加消息不显示任何内容(但消息确实显示在数据库中).

我已经在不使用Picasso的情况下进行了测试,因为只需在应用程序中使用带有图像资源的ImageGetter就可以正常工作,只有它不是来自URL所需.

配置ImageGetter和/或append方法的正确方法是什么,以便此功能可以与Picasso一起使用？或者有更简单的方法吗？

追加方法:

public void appendToMessageHistory(final String username,
            final String message) {
        if (username != null && message != null) {

            Picasso.with(getBaseContext())
                    .load("http://localhost:3000/uploads/campaign/image/2/2.jpg")
                    .into(new Target() {

                        @Override
                        public void onPrepareLoad(Drawable arg0) {

                        }

                        @Override
                        public void onBitmapLoaded(Bitmap bitmap,
                                LoadedFrom arg1) {
                            Drawable drawImage = new BitmapDrawable(
                                    getBaseContext().getResources(), bitmap);

                            drawImage.setBounds(0, 0,
                                    drawImage.getIntrinsicHeight(),
                                    drawImage.getIntrinsicWidth());
                            messageHistoryText.append(Html.fromHtml("<b>"
                                    + username + ":" + "</b>" + "<br>"));
                            messageHistoryText.append(Html.fromHtml(message
                                    + "<hr>" + "<br>")
                                    + System.getProperty("line.separator") + "");

                            messageHistoryText.append(Html
                                    .fromHtml("<img src = '" + drawImage
                                            + "'/>",
                            imageGetter,
                            null));
                        }

                        @Override
                        public void onBitmapFailed(Drawable arg0) {

                        }
                    });

        }
    }

ImageGetter:

ImageGetter imageGetter = new ImageGetter() {
        Drawable imageUsed=null;

        @Override
        public Drawable getDrawable(String source) {

            Picasso.with(getBaseContext())
                    .load("http://localhost:3000/uploads/campaign/image/2/2.jpg")
                    .into(new Target() {

                        @Override
                        public void onPrepareLoad(Drawable arg0) {

                        }

                        @Override
                        public void onBitmapLoaded(Bitmap bitmap,
                                LoadedFrom arg1) {
                            Drawable drawImage = new BitmapDrawable(
                                    getBaseContext().getResources(), bitmap);

                            drawImage.setBounds(0, 0,
                                    drawImage.getIntrinsicHeight(),
                                    drawImage.getIntrinsicWidth());

                            imageUsed=drawImage;

                        }

                        @Override
                        public void onBitmapFailed(Drawable arg0) {

                        }
                    });

            return imageUsed;
        }

    };

Answer 1

我无法使用Picasso的目标......

我的解决方法是:

• 使用AsyncTask进行并发
• 使用Picasso的get()方法在AsyncTask的后台方法中同步加载图像

像这样:

public class PicassoImageGetter implements Html.ImageGetter {

final Resources resources;

final Picasso pablo;

final TextView textView;

public PicassoImageGetter(final TextView textView, final Resources resources, final Picasso pablo) {
    this.textView  = textView;
    this.resources = resources;
    this.pablo     = pablo;
}

@Override public Drawable getDrawable(final String source) {
    final BitmapDrawablePlaceHolder result = new BitmapDrawablePlaceHolder();

    new AsyncTask<Void, Void, Bitmap>() {

        @Override
        protected Bitmap doInBackground(final Void... meh) {
            try {
                return pablo.load(source).get();
            } catch (Exception e) {
                return null;
            }
        }

        @Override
        protected void onPostExecute(final Bitmap bitmap) {
            try {
                final BitmapDrawable drawable = new BitmapDrawable(resources, bitmap);

                drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());

                result.setDrawable(drawable);
                result.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());

                textView.setText(textView.getText()); // invalidate() doesn't work correctly...
            } catch (Exception e) {
                /* nom nom nom*/
            }
        }

    }.execute((Void) null);

    return result;
}

static class BitmapDrawablePlaceHolder extends BitmapDrawable {

    protected Drawable drawable;

    @Override
    public void draw(final Canvas canvas) {
        if (drawable != null) {
            drawable.draw(canvas);
        }
    }

    public void setDrawable(Drawable drawable) {
        this.drawable = drawable;
    }

}

希望这很有用.

Answer 2

我建立在托马斯的回答上.我使用现有的Picasso方法在不同的线程上下载任何图像,并占用了占位符Drawables.

public class PicassoImageGetter implements Html.ImageGetter {
    private TextView textView = null;

    public PicassoImageGetter() {}

    public PicassoImageGetter(TextView target) {
        textView = target;
    }

    @Override
    public Drawable getDrawable(String source) {
        BitmapDrawablePlaceHolder drawable = new BitmapDrawablePlaceHolder();

        Context context = FeedSurferApp.getContext();
        FeedSurferApp
                .getPicasso()
                .load(source)
                .error(ResourcesCompat.getDrawable(context.getResources(), R.drawable.connection_error, context.getTheme()))
                .into(drawable);

        return drawable;
    }

    private class BitmapDrawablePlaceHolder extends BitmapDrawable implements Target {
        protected Drawable drawable;

        @Override
        public void draw(final Canvas canvas) {
            if (drawable != null) {
                drawable.draw(canvas);
            }
        }

        public void setDrawable(Drawable drawable) {
            this.drawable = drawable;
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
            setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
            if (textView != null) {
                textView.setText(textView.getText());
            }
        }

        @Override
        public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
            setDrawable(new BitmapDrawable(FeedSurferApp.getContext().getResources(), bitmap));
        }

        @Override
        public void onBitmapFailed(Drawable errorDrawable) {
            setDrawable(errorDrawable);
        }

        @Override
        public void onPrepareLoad(Drawable placeHolderDrawable) {}
    }
}