Print test

Main page

## MainActivity.java

package net.igonna.androidprint;

import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Window;
import android.view.WindowManager;
import android.webkit.JavascriptInterface;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import android.print.PrintAttributes;   // for_print
import android.print.PrintDocumentAdapter;   // for_print
import android.print.PrintJob;   // for_print
import android.print.PrintManager;   // for_print
import java.util.AbstractList;   // for_print

import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;

public class MainActivity extends AppCompatActivity {
    private WebView webView;
    private WebView newWebView; // 전역변수로 선언해야 "call_print_dialog" 함수에서 사용가능함 for_print edit_20210417
    private BackPressCloseHandler backPressCloseHandler;    // edit_20181211
    private CallFromHtmlJavascriptHandler callFromHtmlJavascriptHandler;    // edit_20190314
    private AbstractList<PrintJob> printJobs;   // for_print
    Handler handler = new Handler();    // for_print

private static final String TAG = "MyWebView";
    public static final String url_home = "http://androidprint.igonna.net";

private int dialog_CLOSE_no = 0;    // edit_20190312

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);
        backPressCloseHandler = new BackPressCloseHandler(this);    // edit_20181211
        callFromHtmlJavascriptHandler = new CallFromHtmlJavascriptHandler(this);    // edit_20190314

webView = (WebView) findViewById(R.id.webView);

webView.addJavascriptInterface(new MyJavaScriptInterface(this), "MyAndroid");     // edit_20190311
        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
        webSettings.setSupportMultipleWindows(true);

webView.setWebViewClient(new WebViewClient() {
            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)    // add code edit_20210128
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                String url = request.getUrl().toString();
                Log.e(TAG,"shouldOverrideUrlLoading url: " + url);
                return false;   // if true, do not move to url
            }
        });

webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onCreateWindow(final WebView view, boolean isDialog, boolean isUserGesture, Message resultMsg) {
                //final WebView newWebView = new WebView(MainActivity.this);          // add to "final"     edit_20190312
                newWebView = new WebView(MainActivity.this);          // add to "final"     edit_20190312       for_print

newWebView.addJavascriptInterface(new MyJavaScriptInterface(MainActivity.this), "MyAndroidForDialog");     // edit_20190311

WebSettings webSettings = newWebView.getSettings();
                webSettings.setJavaScriptEnabled(true);
                webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
                webSettings.setSupportMultipleWindows(true);

newWebView.setScrollBarStyle(newWebView.SCROLLBARS_OUTSIDE_OVERLAY);
                newWebView.setScrollbarFadingEnabled(false);

newWebView.setWebViewClient(new WebViewClient());       // new window open

final Dialog dialog = new Dialog(MainActivity.this);
                dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);   // add dialog_size edit_20190221
                dialog.setContentView(newWebView);

WindowManager.LayoutParams params = dialog.getWindow().getAttributes(); // add dialog_size edit_20190221
                params.width = MATCH_PARENT;       // add dialog_size edit_20190221
                params.height= MATCH_PARENT;      // add dialog_size edit_20190221
                dialog.getWindow().setAttributes(params);       // add dialog_size edit_20190221

dialog.show();

dialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
                    @Override
                    public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
                        if (keyCode == KeyEvent.KEYCODE_BACK) {
                            if (dialog_CLOSE_no == 0) {
                                try {   // try 문 추가(프린터 기능 추가하면서...)  for_print edit_20210417
                                    if(newWebView.canGoBack()) {
                                        //Log.e(TAG,"goback 실행"); // Log.e : 로그 색상이 보라색임
                                        newWebView.goBack();
                                    } else {
                                        //Log.e(TAG,"newwebview close 실행"); // Log.e : 로그 색상이 보라색임
                                        callFromHtmlJavascriptHandler.CallFromHtmlJavascript(newWebView, "window.self.close()");        // edit_20190314
                                        //else dialog.dismiss();    // 이 코드의 오류: dialog 를 처음 띄우고 이 코드가 동작한 후에는 dialog 가 다시 안 뜨는 현상이 발행함
                                    }
                                } catch (Exception e) {
                                    Log.e(TAG,"Error as below"); // todo
                                    e.printStackTrace();
                                    return false;
                                }
                            }
                            dialog_CLOSE_no++;
                            if (dialog_CLOSE_no == 2) dialog_CLOSE_no = 0;
                            return true;
                        }
                        return false;
                    }
                });
                newWebView.setWebChromeClient(new WebChromeClient() {
                    @Override
                    public void onCloseWindow(WebView window) {
                        dialog.dismiss();
                    }
                });
                ((WebView.WebViewTransport) resultMsg.obj).setWebView(newWebView);
                resultMsg.sendToTarget();
                return true;
            }
        });

if (savedInstanceState == null) webView.loadUrl(url_home);
    }

public void onBackPressed() {   // int keyCode, KeyEvent event
        backPressCloseHandler.onBackPressed(webView);
    }

private void showGuide(String txt) {
        Toast.makeText(MainActivity.this, txt, Toast.LENGTH_SHORT).show();
    }

public class MyJavaScriptInterface {      // edit_20190311
        Context mContext;
        MyJavaScriptInterface(Context c) {
            mContext = c;
        }
        @JavascriptInterface
        public void toastLong (String message) {
            Toast.makeText(mContext, message, Toast.LENGTH_LONG).show();
        }
        @JavascriptInterface
        public void toastShort (String message) { // Show toast for a short time
            Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();
        }
        @JavascriptInterface
        public String isSmartPhoneFromAppLocal(String s) { return s; }
        @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
        @JavascriptInterface
        public void call_print_mainView() { // for_print add_20210416
            Log.e(TAG,"start call_print_mainView");
            webView.post(new Runnable() {
                @Override
                public void run() {
                    createWebPrintJob(webView);
                    webView = null;
                }
            });
        }
        @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
        @JavascriptInterface
        public void call_print_dialog() { // for new window(dialog) for_print add_20210416
            Log.e(TAG,"start call_print_dialog");
            handler.post(new Runnable() {
                @Override
                public void run() {
                    createWebPrintJob(newWebView);
                    newWebView = null;
                }
            });
        }
    }

@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public void createWebPrintJob(WebView webView) {    // for_print
        PrintManager printManager = (PrintManager) MainActivity.this
                .getSystemService(Context.PRINT_SERVICE);
        String jobName = getString(R.string.app_name) + " Document";
        PrintDocumentAdapter printAdapter = webView.createPrintDocumentAdapter(jobName);
        PrintJob printJob = printManager.print(jobName, printAdapter,
                new PrintAttributes.Builder().build());
        //printJobs.add(printJob);
    }
}