1. 添加mini demo

2. ui升级到androidx

deploy/android_demo/app/build.gradle

@@ -3,11 +3,11 @@ import java.security.MessageDigest
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 29
     defaultConfig {
         applicationId "com.baidu.paddle.lite.demo.ocr"
-        minSdkVersion 15
-        targetSdkVersion 28
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -39,9 +39,8 @@ android {
 
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
-    implementation 'com.android.support:appcompat-v7:28.0.0'
-    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-    implementation 'com.android.support:design:28.0.0'
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

deploy/android_demo/app/src/main/AndroidManifest.xml

@@ -14,10 +14,10 @@
             android:roundIcon="@mipmap/ic_launcher_round"
             android:supportsRtl="true"
             android:theme="@style/AppTheme">
+        <!-- to test MiniActivity, change this to com.baidu.paddle.lite.demo.ocr.MiniActivity -->
         <activity android:name="com.baidu.paddle.lite.demo.ocr.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
-
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
         </activity>
@@ -26,7 +26,7 @@
                 android:label="Settings">
         </activity>
         <provider
-            android:name="android.support.v4.content.FileProvider"
+            android:name="androidx.core.content.FileProvider"
             android:authorities="com.baidu.paddle.lite.demo.ocr.fileprovider"
             android:exported="false"
             android:grantUriPermissions="true">

deploy/android_demo/app/src/main/java/com/baidu/paddle/lite/demo/ocr/AppCompatPreferenceActivity.java

@@ -19,15 +19,16 @@ package com.baidu.paddle.lite.demo.ocr;
 import android.content.res.Configuration;
 import android.os.Bundle;
 import android.preference.PreferenceActivity;
-import android.support.annotation.LayoutRes;
-import android.support.annotation.Nullable;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AppCompatDelegate;
-import android.support.v7.widget.Toolbar;
 import android.view.MenuInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.LayoutRes;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AppCompatDelegate;
+import androidx.appcompat.widget.Toolbar;
+
 /**
  * A {@link PreferenceActivity} which implements and proxies the necessary calls
  * to be used with AppCompat.

deploy/android_demo/app/src/main/java/com/baidu/paddle/lite/demo/ocr/MainActivity.java

@@ -19,11 +19,6 @@ import android.os.HandlerThread;
 import android.os.Message;
 import android.preference.PreferenceManager;
 import android.provider.MediaStore;
-import android.support.annotation.NonNull;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
-import android.support.v4.content.FileProvider;
-import android.support.v7.app.AppCompatActivity;
 import android.text.method.ScrollingMovementMethod;
 import android.util.Log;
 import android.view.Menu;
@@ -33,6 +28,12 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+import androidx.core.content.FileProvider;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;

deploy/android_demo/app/src/main/java/com/baidu/paddle/lite/demo/ocr/MiniActivity.java

+package com.baidu.paddle.lite.demo.ocr;
+
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Message;
+import android.util.Log;
+import android.view.View;
+import android.widget.Button;
+import android.widget.ImageView;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public class MiniActivity extends AppCompatActivity {
+
+
+    public static final int REQUEST_LOAD_MODEL = 0;
+    public static final int REQUEST_RUN_MODEL = 1;
+    public static final int REQUEST_UNLOAD_MODEL = 2;
+    public static final int RESPONSE_LOAD_MODEL_SUCCESSED = 0;
+    public static final int RESPONSE_LOAD_MODEL_FAILED = 1;
+    public static final int RESPONSE_RUN_MODEL_SUCCESSED = 2;
+    public static final int RESPONSE_RUN_MODEL_FAILED = 3;
+
+    private static final String TAG = "MiniActivity";
+
+    protected Handler receiver = null; // Receive messages from worker thread
+    protected Handler sender = null; // Send command to worker thread
+    protected HandlerThread worker = null; // Worker thread to load&run model
+    protected volatile Predictor predictor = null;
+
+    private String assetModelDirPath = "models/ocr_v1_for_cpu";
+    private String assetlabelFilePath = "labels/ppocr_keys_v1.txt";
+
+    private Button button;
+    private ImageView imageView; // 显示图像
+    private TextView textView; // 显示结果
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_mini);
+
+        Log.i(TAG, "SHOW in Logcat");
+
+        // Prepare the worker thread for mode loading and inference
+        worker = new HandlerThread("Predictor Worker");
+        worker.start();
+        sender = new Handler(worker.getLooper()) {
+            public void handleMessage(Message msg) {
+                switch (msg.what) {
+                    case REQUEST_LOAD_MODEL:
+                        // Load model and reload test image
+                        if (!onLoadModel()) {
+                            runOnUiThread(new Runnable() {
+                                @Override
+                                public void run() {
+                                    Toast.makeText(MiniActivity.this, "Load model failed!", Toast.LENGTH_SHORT).show();
+                                }
+                            });
+                        }
+                        break;
+                    case REQUEST_RUN_MODEL:
+                        // Run model if model is loaded
+                        final boolean isSuccessed = onRunModel();
+                        runOnUiThread(new Runnable() {
+                            @Override
+                            public void run() {
+                                if (isSuccessed){
+                                    onRunModelSuccessed();
+                                }else{
+                                    Toast.makeText(MiniActivity.this, "Run model failed!", Toast.LENGTH_SHORT).show();
+                                }
+                            }
+                        });
+                        break;
+                }
+            }
+        };
+        sender.sendEmptyMessage(REQUEST_LOAD_MODEL); // 对应上面的REQUEST_LOAD_MODEL， 调用onLoadModel()
+
+        imageView = findViewById(R.id.imageView);
+        textView = findViewById(R.id.sample_text);
+        button = findViewById(R.id.button);
+        button.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                sender.sendEmptyMessage(REQUEST_RUN_MODEL);
+            }
+        });
+
+
+    }
+
+    @Override
+    protected void onDestroy() {
+        onUnloadModel();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
+            worker.quitSafely();
+        } else {
+            worker.quit();
+        }
+        super.onDestroy();
+    }
+
+    /**
+     * onCreate的时候调用， 模型初始化
+     *
+     * @return
+     */
+    private boolean onLoadModel() {
+        if (predictor == null) {
+            predictor = new Predictor();
+        }
+        return predictor.init(this, assetModelDirPath, assetlabelFilePath);
+    }
+
+    /**
+     * on
+     *
+     * @return
+     */
+    private boolean onRunModel() {
+        try {
+            String assetImagePath = "images/5.jpg";
+            InputStream imageStream = getAssets().open(assetImagePath);
+            Bitmap image = BitmapFactory.decodeStream(imageStream);
+            // 这里输入是Bitmap
+            predictor.setInputImage(image);
+            return predictor.isLoaded() && predictor.runModel();
+        } catch (IOException e) {
+            e.printStackTrace();
+            return false;
+        }
+    }
+
+    private void onRunModelSuccessed() {
+        Log.i(TAG, "onRunModelSuccessed");
+        textView.setText(predictor.outputResult);
+        imageView.setImageBitmap(predictor.outputImage);
+    }
+
+    private void onUnloadModel() {
+        if (predictor != null) {
+            predictor.releaseModel();
+        }
+    }
+}

deploy/android_demo/app/src/main/java/com/baidu/paddle/lite/demo/ocr/Predictor.java

@@ -38,7 +38,7 @@ public class Predictor {
     protected float scoreThreshold = 0.1f;
     protected Bitmap inputImage = null;
     protected Bitmap outputImage = null;
-    protected String outputResult = "";
+    protected volatile String outputResult = "";
     protected float preprocessTime = 0;
     protected float postprocessTime = 0;
 
@@ -46,6 +46,16 @@ public class Predictor {
     public Predictor() {
     }
 
+    public boolean init(Context appCtx, String modelPath, String labelPath) {
+        isLoaded = loadModel(appCtx, modelPath, cpuThreadNum, cpuPowerMode);
+        if (!isLoaded) {
+            return false;
+        }
+        isLoaded = loadLabel(appCtx, labelPath);
+        return isLoaded;
+    }
+
+
     public boolean init(Context appCtx, String modelPath, String labelPath, int cpuThreadNum, String cpuPowerMode,
                         String inputColorFormat,
                         long[] inputShape, float[] inputMean,
@@ -76,11 +86,7 @@ public class Predictor {
             Log.e(TAG, "Only  BGR color format is supported.");
             return false;
         }
-        isLoaded = loadModel(appCtx, modelPath, cpuThreadNum, cpuPowerMode);
-        if (!isLoaded) {
-            return false;
-        }
-        isLoaded = loadLabel(appCtx, labelPath);
+        boolean isLoaded = init(appCtx, modelPath, labelPath);
         if (!isLoaded) {
             return false;
         }
@@ -317,7 +323,7 @@ public class Predictor {
             for (Point p : result.getPoints()) {
                 sb.append("(").append(p.x).append(",").append(p.y).append(") ");
             }
-            Log.i(TAG, sb.toString());
+            Log.i(TAG, sb.toString()); // 这里在logcat里打印结果
             outputResultSb.append(i + 1).append(": ").append(result.getLabel()).append("\n");
         }
         outputResult = outputResultSb.toString();

deploy/android_demo/app/src/main/java/com/baidu/paddle/lite/demo/ocr/SettingsActivity.java

@@ -5,7 +5,8 @@ import android.os.Bundle;
 import android.preference.CheckBoxPreference;
 import android.preference.EditTextPreference;
 import android.preference.ListPreference;
-import android.support.v7.app.ActionBar;
+
+import androidx.appcompat.app.ActionBar;
 
 import java.util.ArrayList;
 import java.util.List;

deploy/android_demo/app/src/main/res/layout/activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
-<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
                                              xmlns:app="http://schemas.android.com/apk/res-auto"
                                              xmlns:tools="http://schemas.android.com/tools"
                                              android:layout_width="match_parent"
@@ -96,4 +96,4 @@
 
     </RelativeLayout>
 
-</android.support.constraint.ConstraintLayout>
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file

deploy/android_demo/app/src/main/res/layout/activity_mini.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- for MiniActivity Use Only -->
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    app:layout_constraintLeft_toLeftOf="parent"
+    app:layout_constraintLeft_toRightOf="parent"
+    tools:context=".MainActivity">
+
+    <TextView
+        android:id="@+id/sample_text"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:text="Hello World!"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/imageView"
+        android:scrollbars="vertical"
+        />
+
+    <ImageView
+        android:id="@+id/imageView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:paddingTop="20dp"
+        android:paddingBottom="20dp"
+        app:layout_constraintBottom_toTopOf="@id/imageView"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:srcCompat="@tools:sample/avatars" />
+
+    <Button
+        android:id="@+id/button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="4dp"
+        android:text="Button"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        tools:layout_editor_absoluteX="161dp" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file