net.codemirror.lib.Loader.java Source code

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Here is the source code for net.codemirror.lib.Loader.java

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// Copyright (C) 2013 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package net.codemirror.lib;

import com.google.gerrit.client.rpc.CallbackGroup;
import com.google.gwt.core.client.Callback;
import com.google.gwt.core.client.ScriptInjector;
import com.google.gwt.dom.client.ScriptElement;
import com.google.gwt.dom.client.StyleInjector;
import com.google.gwt.resources.client.ExternalTextResource;
import com.google.gwt.resources.client.ResourceCallback;
import com.google.gwt.resources.client.ResourceException;
import com.google.gwt.resources.client.TextResource;
import com.google.gwt.safehtml.shared.SafeUri;
import com.google.gwt.user.client.rpc.AsyncCallback;

import net.codemirror.addon.Addons;

import java.util.logging.Level;
import java.util.logging.Logger;

class Loader {
    private static native boolean isLibLoaded()
    /*-{ return $wnd.hasOwnProperty('CodeMirror'); }-*/;

    static void initLibrary(AsyncCallback<Void> cb) {
        if (isLibLoaded()) {
            cb.onSuccess(null);
        } else {
            CallbackGroup group = new CallbackGroup();
            injectCss(Lib.I.css());
            injectScript(Lib.I.js().getSafeUri(), group.add(new AsyncCallback<Void>() {
                public void onFailure(Throwable caught) {
                }

                public void onSuccess(Void result) {
                }
            }));
            injectScript(Addons.I.mark_selection().getSafeUri(), group.add(cb));
        }
    }

    private static void injectCss(ExternalTextResource css) {
        try {
            css.getText(new ResourceCallback<TextResource>() {
                @Override
                public void onSuccess(TextResource resource) {
                    StyleInjector.inject(resource.getText());
                }

                @Override
                public void onError(ResourceException e) {
                    error(e);
                }
            });
        } catch (ResourceException e) {
            error(e);
        }
    }

    static void injectScript(SafeUri js, final AsyncCallback<Void> callback) {
        final ScriptElement[] script = new ScriptElement[1];
        script[0] = ScriptInjector.fromUrl(js.asString()).setWindow(ScriptInjector.TOP_WINDOW)
                .setCallback(new Callback<Void, Exception>() {
                    @Override
                    public void onSuccess(Void result) {
                        script[0].removeFromParent();
                        callback.onSuccess(result);
                    }

                    @Override
                    public void onFailure(Exception reason) {
                        error(reason);
                        callback.onFailure(reason);
                    }
                }).inject().cast();
    }

    private static void error(Exception e) {
        Logger log = Logger.getLogger("net.codemirror");
        log.log(Level.SEVERE, "Cannot load portions of CodeMirror", e);
    }

    private Loader() {
    }
}