From b894ce4dcd58e337a14b954a0d34997264401df2 Mon Sep 17 00:00:00 2001
From: Nicolas Werner <nicolas.werner@hotmail.de>
Date: Wed, 4 Mar 2020 01:56:58 +0100
Subject: [PATCH] Make blurhash provider async

---
 CMakeLists.txt                           |  1 +
 resources/qml/delegates/ImageMessage.qml |  1 -
 src/BlurhashProvider.cpp                 | 35 ++++++++++------
 src/BlurhashProvider.h                   | 52 +++++++++++++++++++++---
 4 files changed, 69 insertions(+), 20 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5561fc8d..8d0e4477 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -479,6 +479,7 @@ qt5_wrap_cpp(MOC_HEADERS
 	src/notifications/Manager.h
 
 	src/AvatarProvider.h
+	src/BlurhashProvider.h
 	src/Cache_p.h
 	src/ChatPage.h
 	src/CommunitiesList.h
diff --git a/resources/qml/delegates/ImageMessage.qml b/resources/qml/delegates/ImageMessage.qml
index 62cae42c..65e1c454 100644
--- a/resources/qml/delegates/ImageMessage.qml
+++ b/resources/qml/delegates/ImageMessage.qml
@@ -20,7 +20,6 @@ Item {
 		asynchronous: true
 		fillMode: Image.PreserveAspectFit
 
-
 		sourceSize.width: parent.width
 		sourceSize.height: parent.height
 	}
diff --git a/src/BlurhashProvider.cpp b/src/BlurhashProvider.cpp
index 87d1f51b..08dc2d40 100644
--- a/src/BlurhashProvider.cpp
+++ b/src/BlurhashProvider.cpp
@@ -6,24 +6,33 @@
 
 #include "blurhash.hpp"
 
-QImage
-BlurhashProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+void
+BlurhashResponse::run()
 {
-        QSize sz = requestedSize;
-        if (sz.width() < 1 || sz.height() < 1)
-                return QImage();
+        if (m_requestedSize.width() < 0 || m_requestedSize.height() < 0) {
+                m_error = QStringLiteral("Blurhash needs size request");
+                emit finished();
+                return;
+        }
+        if (m_requestedSize.width() == 0 || m_requestedSize.height() == 0) {
+                m_image = QImage(m_requestedSize, QImage::Format_RGB32);
+                m_image.fill(QColor(0, 0, 0));
+                emit finished();
+                return;
+        }
 
-        if (size)
-                *size = sz;
-
-        auto decoded = blurhash::decode(
-          QUrl::fromPercentEncoding(id.toUtf8()).toStdString(), sz.width(), sz.height(), 4);
+        auto decoded = blurhash::decode(QUrl::fromPercentEncoding(m_id.toUtf8()).toStdString(),
+                                        m_requestedSize.width(),
+                                        m_requestedSize.height(),
+                                        4);
         if (decoded.image.empty()) {
-                *size = QSize();
-                return QImage();
+                m_error = QStringLiteral("Failed decode!");
+                emit finished();
+                return;
         }
 
         QImage image(decoded.image.data(), decoded.width, decoded.height, QImage::Format_RGB32);
 
-        return image.copy();
+        m_image = image.copy();
+        emit finished();
 }
diff --git a/src/BlurhashProvider.h b/src/BlurhashProvider.h
index b05fff59..48c945de 100644
--- a/src/BlurhashProvider.h
+++ b/src/BlurhashProvider.h
@@ -1,11 +1,51 @@
-#include <QQuickImageProvider>
+#pragma once
 
-class BlurhashProvider : public QQuickImageProvider
+#include <QQuickAsyncImageProvider>
+#include <QQuickImageResponse>
+
+#include <QImage>
+#include <QThreadPool>
+
+class BlurhashResponse
+  : public QQuickImageResponse
+  , public QRunnable
 {
 public:
-        BlurhashProvider()
-          : QQuickImageProvider(QQuickImageProvider::Image)
-        {}
+        BlurhashResponse(const QString &id, const QSize &requestedSize)
 
-        QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
+          : m_id(id)
+          , m_requestedSize(requestedSize)
+        {
+                setAutoDelete(false);
+        }
+
+        QQuickTextureFactory *textureFactory() const override
+        {
+                return QQuickTextureFactory::textureFactoryForImage(m_image);
+        }
+        QString errorString() const override { return m_error; }
+
+        void run() override;
+
+        QString m_id, m_error;
+        QSize m_requestedSize;
+        QImage m_image;
+};
+
+class BlurhashProvider
+  : public QObject
+  , public QQuickAsyncImageProvider
+{
+        Q_OBJECT
+public slots:
+        QQuickImageResponse *requestImageResponse(const QString &id,
+                                                  const QSize &requestedSize) override
+        {
+                BlurhashResponse *response = new BlurhashResponse(id, requestedSize);
+                pool.start(response);
+                return response;
+        }
+
+private:
+        QThreadPool pool;
 };