Android: Add support for getting information about content uris

This enables things like size(), exists() to work with Android content
uris with the provided uri given from a filedialog. It is expected that
it is always a full path due to the nature of content uris, so relative
paths will not work.

Change-Id: I9c9ea42833677eb9d937b33e9dd42ee2a7d9c7c5
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/android/jar/src/org/qtproject/qt5/android/QtNative.java

@@ -44,6 +44,7 @@ import java.io.File;
 import java.io.FileNotFoundException;
 import java.util.ArrayList;
 import java.util.concurrent.Semaphore;
+import java.io.IOException;
 
 import android.app.Activity;
 import android.app.Service;
@@ -70,6 +71,7 @@ import android.view.Menu;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.InputDevice;
+import android.database.Cursor;
 
 import java.lang.reflect.Method;
 import java.security.KeyStore;
@@ -231,6 +233,61 @@ public class QtNative
         }
     }
 
+    public static long getSize(Context context, String contentUrl)
+    {
+        Uri uri = getUriWithValidPermission(context, contentUrl, "r");
+        long size = -1;
+
+        if (uri == null) {
+            Log.e(QtTAG, "getSize(): No permissions to open Uri");
+            return size;
+        }
+
+        try {
+            ContentResolver resolver = context.getContentResolver();
+            Cursor cur = resolver.query(uri, null, null, null, null);
+            if (cur != null) {
+                if (cur.moveToFirst())
+                    size = cur.getLong(5); // size column
+                cur.close();
+            }
+            return size;
+        } catch (IllegalArgumentException e) {
+            Log.e(QtTAG, "getSize(): Invalid Uri");
+            return size;
+        }  catch (UnsupportedOperationException e) {
+            Log.e(QtTAG, "getSize(): Unsupported operation for given Uri");
+            return size;
+        }
+    }
+
+    public static boolean checkFileExists(Context context, String contentUrl)
+    {
+        Uri uri = getUriWithValidPermission(context, contentUrl, "r");
+        boolean exists = false;
+
+        if (uri == null) {
+            Log.e(QtTAG, "checkFileExists(): No permissions to open Uri");
+            return exists;
+        }
+
+        try {
+            ContentResolver resolver = context.getContentResolver();
+            Cursor cur = resolver.query(uri, null, null, null, null);
+            if (cur != null) {
+                exists = true;
+                cur.close();
+            }
+            return exists;
+        } catch (IllegalArgumentException e) {
+            Log.e(QtTAG, "checkFileExists(): Invalid Uri");
+            return exists;
+        } catch (UnsupportedOperationException e) {
+            Log.e(QtTAG, "checkFileExists(): Unsupported operation for given Uri");
+            return false;
+        }
+    }
+
     // this method loads full path libs
     public static void loadQtLibraries(final ArrayList<String> libraries)
     {

src/plugins/platforms/android/androidcontentfileengine.cpp

@@ -44,9 +44,10 @@
 
 #include <QDebug>
 
-AndroidContentFileEngine::AndroidContentFileEngine(const QString &fileName)
+AndroidContentFileEngine::AndroidContentFileEngine(const QString &f)
-    : QFSFileEngine(fileName)
+    : m_file(f)
 {
+    setFileName(f);
 }
 
 bool AndroidContentFileEngine::open(QIODevice::OpenMode openMode)
@@ -78,6 +79,48 @@ bool AndroidContentFileEngine::open(QIODevice::OpenMode openMode)
     return QFSFileEngine::open(openMode, fd, QFile::AutoCloseHandle);
 }
 
+qint64 AndroidContentFileEngine::size() const
+{
+    const jlong size = QJNIObjectPrivate::callStaticMethod<jlong>(
+            "org/qtproject/qt5/android/QtNative", "getSize",
+            "(Landroid/content/Context;Ljava/lang/String;)J", QtAndroidPrivate::context(),
+            QJNIObjectPrivate::fromString(fileName(DefaultName)).object());
+    return (qint64)size;
+}
+
+AndroidContentFileEngine::FileFlags AndroidContentFileEngine::fileFlags(FileFlags type) const
+{
+    FileFlags commonFlags(ReadOwnerPerm|ReadUserPerm|ReadGroupPerm|ReadOtherPerm|ExistsFlag);
+    FileFlags flags;
+    const bool exists = QJNIObjectPrivate::callStaticMethod<jboolean>(
+            "org/qtproject/qt5/android/QtNative", "checkFileExists",
+            "(Landroid/content/Context;Ljava/lang/String;)Z", QtAndroidPrivate::context(),
+            QJNIObjectPrivate::fromString(fileName(DefaultName)).object());
+    if (!exists)
+        return flags;
+    flags = FileType | commonFlags;
+    return type & flags;
+}
+
+QString AndroidContentFileEngine::fileName(FileName f) const
+{
+    switch (f) {
+        case PathName:
+        case AbsolutePathName:
+        case CanonicalPathName:
+        case DefaultName:
+        case AbsoluteName:
+        case CanonicalName:
+            return m_file;
+        case BaseName:
+        {
+            const int pos = m_file.lastIndexOf(QChar(QLatin1Char('/')));
+            return m_file.mid(pos);
+        }
+        default:
+            return QString();
+    }
+}
 
 AndroidContentFileEngineHandler::AndroidContentFileEngineHandler() = default;
 AndroidContentFileEngineHandler::~AndroidContentFileEngineHandler() = default;

src/plugins/platforms/android/androidcontentfileengine.h

@@ -47,6 +47,12 @@ class AndroidContentFileEngine : public QFSFileEngine
 public:
     AndroidContentFileEngine(const QString &fileName);
     bool open(QIODevice::OpenMode openMode) override;
+    qint64 size() const override;
+    FileFlags fileFlags(FileFlags type = FileInfoAll) const override;
+    QString fileName(FileName file = DefaultName) const override;
+private:
+    QString m_file;
+
 };
 
 class AndroidContentFileEngineHandler : public QAbstractFileEngineHandler