use appcompat classes as parent

src/main/java/com/owncloud/android/ui/SquareImageView.java

@@ -19,10 +19,10 @@
 package com.owncloud.android.ui;
 
 import android.content.Context;
+import android.support.v7.widget.AppCompatImageView;
 import android.util.AttributeSet;
-import android.widget.ImageView;
 
-public class SquareImageView extends ImageView {
+public class SquareImageView extends AppCompatImageView {
 
     public SquareImageView(Context context) {
         super(context);

src/main/java/com/owncloud/android/ui/preview/ImageViewCustom.java

@@ -5,16 +5,16 @@ import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Movie;
 import android.os.Build;
+import android.support.v7.widget.AppCompatImageView;
 import android.util.AttributeSet;
 import android.view.View;
-import android.widget.ImageView;
 
 import com.owncloud.android.lib.common.utils.Log_OC;
 
 import java.io.FileInputStream;
 import java.io.InputStream;
 
-public class ImageViewCustom extends ImageView {
+public class ImageViewCustom extends AppCompatImageView {
 
     private static final String TAG = ImageViewCustom.class.getSimpleName();
 

src/main/java/com/owncloud/android/widgets/ActionEditText.java

@@ -25,9 +25,9 @@ import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Rect;
+import android.support.v7.widget.AppCompatEditText;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
-import android.widget.EditText;
 
 import com.owncloud.android.R;
 import com.owncloud.android.lib.common.utils.Log_OC;
@@ -35,7 +35,7 @@ import com.owncloud.android.lib.common.utils.Log_OC;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
-public class ActionEditText extends EditText {
+public class ActionEditText extends AppCompatEditText {
     private String s;
     private String optionOneString;
     private int optionOneColor;