👃🏻 👲 🌳 Foto dari smartphone Android di Qt Widgets 🎡 👃🏼 🌗

Jika Anda tidak punya waktu untuk membaca atau jika Anda mengetahui informasinya, kode terakhir untuk mendapatkan gambar ukuran penuh dari kamera smartphone Android ada di akhir artikel.

Deskripsi masalah

Jika Anda menulis aplikasi lintas platform, Anda dapat menggunakan kelas QCamera untuk mendapatkan gambar dari kamera PC , contohnya dijelaskan dalam dokumentasi Qt.

Menurut contoh di atas, kami menambahkan ke file .pro

QT += multimedia multimediawidgets

Selanjutnya, kami membuat widget di program kami yang menampilkan gambar dari webcam dan menyimpannya dalam QPixmap atau QImage untuk digunakan di masa mendatang.

Ketika muncul tugas untuk melakukan hal yang sama di Android, ternyata widget multimedia tidak didukung oleh OS ini dan kamera akan mengambil dan menyimpan gambar, tetapi apa yang ditampilkannya saat ini akan menjadi misteri, karena QCameraViewfinder menggunakan widget multimedia dan tidak. tidak ditampilkan di Android. Pencarian lebih lanjut untuk solusi masalah mengarah ke dua solusi:

gunakan QML dan tulis Qt Quick-element Anda sendiri yang menjalankan fungsi ini, lalu gabungkan dengan aplikasi lainnya di Qt Widgets , C ++;
gunakan aplikasi bawaan smartphone Android untuk menerima foto, lalu proses di aplikasi Anda.

Pertimbangkan opsi pertama

Jika Anda adalah programmer C ++ dari Qt Widgets , maka pendalaman episodik berikutnya ke dalam QML akan memakan waktu, tambahkan waktu ini untuk menulis elemen Qt Quick , gabungkan elemen ini dengan kode C ++, debug kode tertulis. Jika Anda bukan seorang profesional dalam QML, prosesnya akan lama dan sulit.

Pertimbangkan opsi kedua

Android- -, , , Java- (JNI — Java Native Interface) ++ QtAndroid. . , , , Android .

, Android- .

Android , . , GitHub , . , , FileUriExposedException , .

, , , Java- — .

.pro .

Android.

android {
    QT       +=androidextras
}

, QAndroidActivityResultReceiver. , , Qt, QObject.

(.h) :

#ifndef CAMSHOT_H
#define CAMSHOT_H
#include <QObject>
#include <QString>
#include <cstring>
#include <QImage>
#include <QDebug>
#include <QtAndroid>
#include <QAndroidActivityResultReceiver>
#include <QAndroidParcel>
class CamShot : public QObject, public QAndroidActivityResultReceiver
{
    Q_OBJECT
public:
    CamShot(QObject *parent = nullptr):QObject(parent),QAndroidActivityResultReceiver(){}
    
    static const int RESULT_OK = -1; 
    static const int REQUEST_IMAGE_CAPTURE = 1;
    static const int REQUEST_TAKE_PHOTO = REQUEST_IMAGE_CAPTURE;
    void handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data)  override;
    static QImage camThumbnailToQImage(const QAndroidJniObject &data);
public slots:
    void aMakeShot();
signals:
    void createNew(const QImage &img);
};

#endif // CAMSHOT_H

(.cpp) :

QImage CamShot::camThumbnailToQImage(const QAndroidJniObject &data){
    QAndroidJniObject bundle = data.callObjectMethod("getExtras","()Landroid/os/Bundle;");
    qDebug()<<"bundle.isValid() "<<bundle.isValid()<<bundle.toString();
    QAndroidJniObject bundleKey = QAndroidJniObject::fromString("data");
    const QAndroidJniObject aBitmap (data.callObjectMethod("getParcelableExtra", "(Ljava/lang/String;)Landroid/os/Parcelable;", bundleKey.object<jstring>()));
    qDebug()<<"aBitmap.isValid() "<<aBitmap.isValid()<<aBitmap.toString();
    jint aBitmapWidth = aBitmap.callMethod<jint>("getWidth");
    jint aBitmapHeight = aBitmap.callMethod<jint>("getHeight");
    QAndroidJniEnvironment env;
    const int32_t aBitmapPixelsCount = aBitmapWidth * aBitmapHeight;
    jintArray pixels = env->NewIntArray(aBitmapPixelsCount);
    jint aBitmapOffset = 0;
    jint aBitmapStride = aBitmapWidth;
    jint aBitmapX = 0;
    jint aBitmapY = 0;
    aBitmap.callMethod<void>("getPixels","([IIIIIII)V", pixels, aBitmapOffset, aBitmapStride, aBitmapX, aBitmapY, aBitmapWidth, aBitmapHeight);
    jint *pPixels = env->GetIntArrayElements(pixels, nullptr);
    QImage img(aBitmapWidth, aBitmapHeight, QImage::Format_ARGB32);
    int lineSzB = aBitmapWidth * sizeof(jint);
    for (int i = 0; i < aBitmapHeight; ++i){
        uchar *pDst = img.scanLine(i);
        const uchar *pSrc = reinterpret_cast<const uchar*>(pPixels + aBitmapWidth * i + aBitmapWidth);
        memcpy(pDst, pSrc, lineSzB);
    }
    env->DeleteLocalRef(pixels); //env->ReleaseIntArrayElements(pixels, pPixels, 0);       ,     ,  DeleteLocalRef.

    return img;
}
void CamShot::aMakeShot() {
    QAndroidJniObject action = QandroidJniObject::fromString("android.media.action.IMAGE_CAPTURE");
    //   Java- (  ),      (-   "/"),   "android/content/Intent", "java/lang/String".
    //   Java-,       "L"  ";"  ,  "Landroid/content/Intent ;", "Ljava/lang/String;".
    //    ,      ,  "V" (void)  "[IIIIIII" ( jint,  6 jint  )
    //,   :
    QAndroidJniObject intent=QAndroidJniObject("android/content/Intent","(Ljava/lang/String;)V", action.object<jstring>());
    QtAndroid::startActivity(intent, REQUEST_IMAGE_CAPTURE, this);
}
void CamShot::handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data){
    if ( receiverRequestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK )
    {
        const QImage thumbnail (camThumbnailToQImage(data));
        if (!thumbnail.isNull())
            emit createNew(thumbnail);
    }
}

JNI-

Java- ( Java-), (- "/"), "android/content/Intent", "java/lang/String";
Java-, "L" ";" , "Landroid/content/Intent;", "Ljava/lang/String;";
, ( ), "V" (void), "I" (jint) "[IIIIIII" ( jint, 6 jint );

C/C++	JNI	Java	Signature
uint8_t/unsigned char	jboolean	bool	Z
int8_t/char/signed char	jbyte	byte	B
uint16_t/unsigned short	jchar	char	C
int16_t/short	jshort	short	S
int32_t/int/(long)	jint	int	I
int64_t/(long)/long long	jlong	long	J
float	jfloat	float	F
double	jdouble	double	D
void		void	V

JNI	Java	Signature
jbooleanArray	bool[]	[Z
jbyteArray	byte[]	[B
jcharArray	char[]	[C
jshortArray	short[]	[S
jintArray	int[]	[I
jlongArray	long[]	[L
jfloatArray	float[]	[F
jdoubleArray	double[]	[D
jarray	type[]	[Lfully/qualified/type/name;
jarray	String[]	[Ljava/lang/String;

, JNI- QAndroidJniEnvironment, : NewIntArray, GetIntArrayElements, DeleteLocalRef GetArrayLength,GetObjectArrayElement, SetObjectArrayElement, ..

(pdf) Practical Qt on Android JNI — qtcon.

class CamShot :

, Android ( Java-);
void handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data) override;

Java- Intent ;
static QImage camThumbnailToQImage(const QAndroidJniObject &data);

Java- Intent Java- Bitmap, (32- ) QImage;
void aMakeShot();

;
void createNew(const QImage &img);

.

void aMakeShot() Java- Intent , , — . (Intent) (Activity).

- . , handleActivityResult, : . , camThumbnailToQImage QImage Java- Bitmap Qt.

static QImage camThumbnailToQImage(const QAndroidJniObject &data) override;

Java- Intent Java- Bundle, Intent:

Bundle getExtras()

Bundle <->:<>. Android , . "data".

Java- Bitmap , Intent:

T getParcelableExtra (String name)

C Bitmap QImage , . . Bitmap . ( ) QImage .

Bitmap QImage Bitmap:

void getPixels (int[] pixels, int offset, int stride, int x, int y, int width, int height)

jintArray pixels = env->NewIntArray(aBitmapPixelsCount);

, , , C++ :

jint *pPixels = env->GetIntArrayElements(pixels, nullptr);

Qimage. ,

env->DeleteLocalRef(pixels);

QImage.

. .

FileProvider, Uri . , Android, , :

androidx.core.content.FileProvider;
android.support.v4.content.FileProvider.

— , Qt, QtCreator:

()→ «» → «» → «»→ «Android»→ «SDK Manager»→ «» → «Extras»→ «Android Support Repository» - «» .

Android

QtCreator «». « »→ «». «Build Android APK» → «Create Templates». « Gradle Android», «»:

«android», .

Android

- Android, .pro android: :

android {
    QT       +=androidextras
}
# … 
DISTFILES += \
android:    android/AndroidManifest.xml \
android:    android/build.gradle \
android:    android/gradle/wrapper/gradle-wrapper.jar \
android:    android/gradle/wrapper/gradle-wrapper.properties \
android:    android/gradlew \
android:    android/gradlew.bat \
android:    android/res/values/libs.xml \
    todo.txt

AndroidManifest.xml

«AndroidManifest.xml» android/AndroidManifest.xml,

</activity>
<!-- For adding service(s) please check: https://wiki.qt.io/AndroidServices ->

<provider android:name="android.support.v4.content.FileProvider" android:authorities="org.qtproject.example.qsketch.fileprovider" android:grantUriPermissions="true" android:exported="false">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"/>
</provider>

, - .

, «AndroidManifest.xml» «res» «values», «xml», «file_paths.xml» (… /abin/AndroidManifest.xml) (… /abin/res/xml/file_paths.xml). :

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-files-path name="shared" path="shared/" />
</paths>

shared/

, FileProvider

android/build.gradle, dependencies :

compile'com.android.support:support-v4:25.3.1'

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
compile'com.android.support:support-v4:25.3.1'
}

, Android Support Repository.

Sharing Files on Android or iOS from or with your Qt App - Part 4 .

(.h) :

#ifndef CAMSHOT_H
#define CAMSHOT_H
#include <QObject>
#include <QImage>
#include <QString>
#include <QDebug>

#include <QtAndroid>
#include <QAndroidActivityResultReceiver>
#include <QAndroidParcel>

#include "auxfunc.h"

class CamShot : public QObject, public QAndroidActivityResultReceiver
{
    Q_OBJECT
public:
    static const int RESULT_OK = -1;
    static const int REQUEST_IMAGE_CAPTURE = 1;
    static const int REQUEST_TAKE_PHOTO = REQUEST_IMAGE_CAPTURE;
    enum ImgOrientation {ORIENTATION_UNDEFINED = 0, ORIENTATION_NORMAL = 1, ORIENTATION_FLIP_HORIZONTAL = 2, ORIENTATION_ROTATE_180 = 3, ORIENTATION_FLIP_VERTICAL = 4, ORIENTATION_TRANSPOSE = 5,
                       ORIENTATION_ROTATE_90 = 6, ORIENTATION_TRANSVERSE = 7, ORIENTATION_ROTATE_270 = 8};
    void handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data) override;
    static QImage aBitmapToQImage(const QAndroidJniObject &aBitmap);
    static QImage camThumbnailToQImage(const QAndroidJniObject &data);
    ImgOrientation needRotateAtRightAngle();
    QImage camImageToQImage();
    static void applyOrientation(QImage &img, const ImgOrientation &orientation);


    explicit CamShot(QObject *parent = nullptr):QObject(parent),QAndroidActivityResultReceiver(){}
    ~CamShot();
private:    
    QAndroidJniObject tempImgURI;
    QAndroidJniObject tempImgFile;
    QAndroidJniObject tempImgAbsPath;
    bool _thumbnailNotFullScaleRequested;
public slots:
    void aMakeShot(const bool &thumbnailNotFullScale = false);
signals:
    void createNew(const QImage &img);
};
#endif // CAMSHOT_H

(.cpp) :

QImage CamShot::aBitmapToQImage(const QAndroidJniObject &aBitmap){
    if (!aBitmap.isValid())
        return QImage();
    jint aBitmapWidth = aBitmap.callMethod<jint>("getWidth");
    jint aBitmapHeight = aBitmap.callMethod<jint>("getHeight");
    QAndroidJniEnvironment env;
    const int32_t aBitmapPixelsCount = aBitmapWidth * aBitmapHeight;
    jintArray pixels = env->NewIntArray(aBitmapPixelsCount);
    jint aBitmapOffset = 0;
    jint aBitmapStride = aBitmapWidth;
    jint aBitmapX = 0;
    jint aBitmapY = 0;
    aBitmap.callMethod<void>("getPixels","([IIIIIII)V", pixels, aBitmapOffset, aBitmapStride, aBitmapX, aBitmapY, aBitmapWidth, aBitmapHeight);
    jint *pPixels = env->GetIntArrayElements(pixels, nullptr);
    QImage img(aBitmapWidth, aBitmapHeight, QImage::Format_ARGB32);
    int lineSzB = aBitmapWidth * sizeof(jint);
    for (int i = 0; i < aBitmapHeight; ++i){
        uchar *pDst = img.scanLine(i);
        const uchar *pSrc = reinterpret_cast<const uchar*>(pPixels + aBitmapWidth * i + aBitmapWidth);
        memcpy(pDst, pSrc, lineSzB);
    }
    env->DeleteLocalRef(pixels); //env->ReleaseIntArrayElements(pixels, pPixels, 0);       ,     ,  DeleteLocalRef.
    return img;
}
QImage CamShot::camThumbnailToQImage(const QAndroidJniObject &data){
    //  
    QAndroidJniObject bundle = data.callObjectMethod("getExtras","()Landroid/os/Bundle;");
    qDebug()<<"bundle.isValid() "<<bundle.isValid()<<bundle.toString();
    //   jstring ( Java)   "data" -        <, >  -   Bitmap (Java)
    QAndroidJniObject bundleKey = QAndroidJniObject::fromString("data");
    //   "data"  :     Bitmap
    const QAndroidJniObject aBitmap (data.callObjectMethod("getParcelableExtra", "(Ljava/lang/String;)Landroid/os/Parcelable;", bundleKey.object<jstring>()));
    qDebug()<<"aBitmap.isValid() "<<aBitmap.isValid()<<aBitmap.toString();
    return aBitmapToQImage(aBitmap);
}
QImage CamShot::camImageToQImage(){
    QAndroidJniObject bitmap = QAndroidJniObject::callStaticObjectMethod("android/graphics/BitmapFactory","decodeFile","(Ljava/lang/String;)Landroid/graphics/Bitmap;",tempImgAbsPath.object<jobject>());
    qDebug()<<"bitmap.isValid() "<<bitmap.isValid()<<bitmap.toString();
    QImage img = aBitmapToQImage(bitmap);
    // 
    if (tempImgFile.isValid())
        tempImgFile.callMethod<jboolean>("delete");
    return img;
}
CamShot::ImgOrientation CamShot::needRotateAtRightAngle(){
    //  
    QAndroidJniObject exifInterface = QAndroidJniObject("android/media/ExifInterface","(Ljava/lang/String;)V",
                                                     tempImgAbsPath.object<jstring>());
    qDebug() << __FUNCTION__ << "exifInterface.isValid()=" << exifInterface.isValid();
    QAndroidJniObject TAG_ORIENTATION = QAndroidJniObject::getStaticObjectField<jstring>("android/media/ExifInterface", "TAG_ORIENTATION");
    qDebug() << __FUNCTION__ << "TAG_ORIENTATION.isValid()=" << TAG_ORIENTATION.isValid()<<TAG_ORIENTATION.toString();
    const jint orientation = exifInterface.callMethod<jint>("getAttributeInt","(Ljava/lang/String;I)I",TAG_ORIENTATION.object<jstring>(),static_cast<jint>(ORIENTATION_UNDEFINED));
    return static_cast<ImgOrientation>(orientation);
}
void CamShot::applyOrientation(QImage &img, const ImgOrientation &orientation){
    switch (orientation){
    case ORIENTATION_UNDEFINED:
    case ORIENTATION_NORMAL:
        break;
    case ORIENTATION_FLIP_HORIZONTAL:{
        img = img.mirrored(true, false);
        break;
    }
    case ORIENTATION_ROTATE_180:
        Aux::rotateImgCW180(img);
        break;
    case ORIENTATION_FLIP_VERTICAL:{
        img = img.mirrored(false, true);
        break;
    }
    case ORIENTATION_TRANSPOSE:{
        img = img.mirrored(true, false);
        Aux::rotateImgCW270(img);
        break;
    }
    case ORIENTATION_ROTATE_90:
        Aux::rotateImgCW90(img);
        break;
    case ORIENTATION_TRANSVERSE:{
        img = img.mirrored(true, false);
        Aux::rotateImgCW90(img);
        break;
    }
        break;
    case ORIENTATION_ROTATE_270:
        Aux::rotateImgCW270(img);
        break;
    }
}
void CamShot::handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data){
    if ( receiverRequestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK )
    {
        if (_thumbnailNotFullScaleRequested){
            const QImage thumbnail (camThumbnailToQImage(data));
            if (!thumbnail.isNull())
                emit createNew(thumbnail);
            return;
        }
        const ImgOrientation orientation = needRotateAtRightAngle();
        QImage image (camImageToQImage());
        if (!image.isNull()){
            applyOrientation(image, orientation);
            emit createNew(image);
        }
    }
}
void CamShot::aMakeShot(const bool &thumbnailNotFullScale) {
    QAndroidJniObject action = QAndroidJniObject::fromString("android.media.action.IMAGE_CAPTURE");
    //  
    QAndroidJniObject intent=QAndroidJniObject("android/content/Intent","(Ljava/lang/String;)V",
                                                 action.object<jstring>());
    qDebug() << __FUNCTION__ << "intent.isValid()=" << intent.isValid();
    _thumbnailNotFullScaleRequested = thumbnailNotFullScale;
    if (thumbnailNotFullScale) {
        //  
        QtAndroid::startActivity(intent, REQUEST_IMAGE_CAPTURE, this);
        return;
    }
    //    
    QAndroidJniObject context = QtAndroid::androidContext();
    QString contextStr (context.toString());
    qDebug() <<"Context: "<<contextStr;
    //    
    QAndroidJniObject extDir = context.callObjectMethod("getExternalFilesDir", "(Ljava/lang/String;)Ljava/io/File;", NULL);
    qDebug() << __FUNCTION__ << "extDir.isValid()=" << extDir.isValid()<<extDir.toString();
    //          
    QAndroidJniObject extDirAbsPath = extDir.callObjectMethod("getAbsolutePath","()Ljava/lang/String;");
    //          . . /res/xml/file_paths.xml
    extDirAbsPath = QAndroidJniObject::fromString(extDirAbsPath.toString() + "/shared");
    const QString extDirAbsPathStr = extDirAbsPath.toString();
    qDebug() << __FUNCTION__ << "extDirAbsPath.isValid()=" << extDirAbsPath.isValid()<<extDirAbsPathStr;
    //      
    QAndroidJniObject sharedFolder=QAndroidJniObject("java.io.File","(Ljava/lang/String;)V",
                                                      extDirAbsPath.object<jstring>());
    qDebug() << __FUNCTION__ << "sharedFolder.isValid()=" << sharedFolder.isValid()<<sharedFolder.toString();
    const jboolean sharedFolderCreated = sharedFolder.callMethod<jboolean>("mkdirs");
    Q_UNUSED(sharedFolderCreated);
    //       ,        
    //    
    QAndroidJniObject suggestedFilePath = QAndroidJniObject::fromString(extDirAbsPathStr+"/"+"_tmp.jpg");
    qDebug() << __FUNCTION__ << "suggestedFilePath.isValid()=" << suggestedFilePath.isValid()<<suggestedFilePath.toString();
    //   
    //  
    QAndroidJniObject tempImgFile=QAndroidJniObject("java.io.File","(Ljava/lang/String;)V",
                                                 suggestedFilePath.object<jstring>());
    qDebug() << __FUNCTION__ << "fileExistsCheck.isValid()=" << tempImgFile.isValid()<<tempImgFile.toString();
    // ,   
    if (tempImgFile.isValid()){
        const jboolean deleted = tempImgFile.callMethod<jboolean>("delete");
        Q_UNUSED(deleted);
    }
    //          
    const jboolean fileCreated = tempImgFile.callMethod<jboolean>("createNewFile");
    Q_UNUSED(fileCreated);
    //       
    tempImgAbsPath = tempImgFile.callObjectMethod("getAbsolutePath","()Ljava/lang/String;");
    qDebug() << __FUNCTION__ << "tempImgAbsPath.isValid()=" << tempImgAbsPath.isValid()<<tempImgAbsPath.toString();
    // authority  fileprovider
    const QString contextFileProviderStr ("org.qtproject.example.qsketch.fileprovider");
    const char androidFileProvider  [] = "android/support/v4/content/FileProvider";
    //const char androidxFileProvider [] = "androidx/core/content/FileProvider"; -   Qt
    /*QAndroidJniObject*/ tempImgURI = QAndroidJniObject::callStaticObjectMethod(androidFileProvider, "getUriForFile", "(Landroid/content/Context;Ljava/lang/String;Ljava/io/File;)Landroid/net/Uri;",
                                                                             context.object<jobject>(), QAndroidJniObject::fromString(contextFileProviderStr).object<jstring>(), tempImgFile.object<jobject>());
    qDebug() << __FUNCTION__ << "tempImgURI.isValid()=" << tempImgURI.isValid()<<tempImgURI.toString();
    //   MediaStore.EXTRA_OUTPUT
    QAndroidJniObject MediaStore__EXTRA_OUTPUT
        = QAndroidJniObject::getStaticObjectField("android/provider/MediaStore", "EXTRA_OUTPUT", "Ljava/lang/String;");
    qDebug() << "MediaStore__EXTRA_OUTPUT.isValid()=" << MediaStore__EXTRA_OUTPUT.isValid();
    // URI         
    intent.callObjectMethod("putExtra","(Ljava/lang/String;Landroid/os/Parcelable;)Landroid/content/Intent;",MediaStore__EXTRA_OUTPUT.object<jstring>(), tempImgURI.object<jobject>());
    qDebug() << __FUNCTION__ << "intent.isValid()=" << intent.isValid();
    QtAndroid::startActivity(intent, REQUEST_IMAGE_CAPTURE, this);
}

- Aux .

(.h) Aux :

#ifndef AUXFUNC_H
#define AUXFUNC_H

#include <QImage>
#include <QColor>
#include <QPainter>
#include <QMatrix>
#include <QSize>
#include <QPoint>

class Aux
{
public:
    static void resizeCenteredImg(QImage *image, const QSize &newSize, const QColor bgColor);
    static void rotateImg(QImage &img, qreal degrees);
    static void rotateImgCW90(QImage &img);
    static void rotateImgCW180(QImage &img);
    static void rotateImgCW270(QImage &img);
};


#endif // AUXFUNC_H

(.cpp) Aux :

void Aux::resizeCenteredImg(QImage *image, const QSize &newSize, const QColor bgColor){
    if (image->size() == newSize)
        return;
    const QSize szDiff = newSize - image->size();
    QImage newImage(newSize, QImage::Format_ARGB32);
    newImage.fill(bgColor);
    QPainter painter(&newImage);
    painter.drawImage(QPoint(szDiff.width()/2, szDiff.height()/2), *image);
    *image = newImage;
}
void Aux::rotateImg(QImage &img, qreal degrees){
    QPoint center = img.rect().center();
    QMatrix matrix;
    matrix.translate(center.x(), center.y());
    matrix.rotate(degrees);
    img = img.transformed(matrix, Qt::SmoothTransformation);
}
void Aux::rotateImgCW90(QImage &img){
    const int w = img.width();
    const int h = img.height();
    const int maxDim = std::max(w, h);
    resizeCenteredImg(&img, QSize(maxDim, maxDim), Qt::white);
    rotateImg(img, 90);
    resizeCenteredImg(&img, QSize(h, w), Qt::white);
}
void Aux::rotateImgCW180(QImage &img){
    rotateImg(img, 180);
}
void Aux::rotateImgCW270(QImage &img){
    const int w = img.width();
    const int h = img.height();
    const int maxDim = std::max(w, h);
    resizeCenteredImg(&img, QSize(maxDim, maxDim), Qt::white);
    rotateImg(img, 270);
    resizeCenteredImg(&img, QSize(h, w), Qt::white);
}

«thumbnailNotFullScale». , , , . JNI-.

Jika gambar kecil selalu diorientasikan dengan benar, maka gambar ukuran penuh diarahkan ke satu arah dan harus diputar. Informasi tentang transformasi yang diperlukan dapat diperoleh dari properti exif gambar menggunakan ExifInterface . Dalam contoh Java yang ditemukan di Internet , konversi ke orientasi normal dilakukan dalam kode Java, dalam kasus Qt tidak ada gunanya menyiksa diri Anda dengan panggilan JNI yang sulit dan rumit, dan lebih mudah untuk melakukan semua transformasi yang diperlukan di Qt.

Foto dari smartphone Android di Qt Widgets

Deskripsi masalah

Pertimbangkan opsi pertama

Pertimbangkan opsi kedua

JNI-

Android

Android

AndroidManifest.xml

, FileProvider

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