Implemented PictureViewer class

Don't call an external program for showing a picture. When an image is
doubleclicked a new windows shows the picture. Pictures can still be
opened in an exteral program by using the "Open with..." context menu
item.

1 files changed, 170 insertions, 0 deletions

diff --git a/pictureviewer.cpp b/pictureviewer.cpp
new file mode 100644
index 0000000..74a06c5
--- /dev/null
+++ b/pictureviewer.cpp
@@ -0,0 +1,170 @@
+/*
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License
+  as published by the Free Software Foundation; either version
+  2 of the License, or (at your option) any later version.
+*/
+
+#include <QGraphicsScene>
+#include <QGraphicsPixmapItem>
+#include <QFileInfo>
+#include <QLinearGradient>
+#include <QDesktopWidget>
+#include <QApplication>
+#include <QDir>
+#include <QWheelEvent>
+
+#include <algorithm>
+
+#include "pictureviewer.h"
+#include "pictureviewerinfoitem.h"
+#include "helper.h"
+
+PictureViewer::PictureViewer(QWidget *parent) : QGraphicsView(parent), mCurrentPic(0), mInfoItem(0) {
+	mScene = new QGraphicsScene(this);
+	setScene(mScene);
+}
+
+void PictureViewer::showPic(const QString &path){
+	QFileInfo fi(path);
+	if(!fi.exists() || fi.isDir()){
+		return;
+	}
+	QPixmap img(path);
+	if(img.isNull()){
+		return;
+	}
+
+	if(mCurrentPic){
+		mScene->removeItem(mCurrentPic);
+		mScene->removeItem(mInfoItem);
+		delete mCurrentPic;
+		delete mInfoItem;
+		mCurrentPic = 0;
+		mInfoItem = 0;
+	}
+
+	setDir(path);
+	if(!isVisible()){
+		show();
+	}
+
+	QSize maxSize;
+	QDesktopWidget *desktopWidget = QApplication::desktop();
+	QSize desktopSize = desktopWidget->availableGeometry().size();
+	if((img.height() > desktopSize.height()) || (img.width() > desktopSize.height())){
+		maxSize = desktopSize;
+	}else{
+		maxSize = img.size();
+	}
+
+	if(img.width() > maxSize.width() || img.height() > maxSize.height()){
+		img = img.scaled(maxSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+	}
+
+	resize(img.size() + QSize(20, 20));
+	setSceneRect(viewport()->rect());
+	QGraphicsPixmapItem *item = new QGraphicsPixmapItem(img);
+	mCurrentPic = item;
+	item->setPos(center(img));
+	mScene->addItem(item);
+
+	PictureviewerInfoItem *infoItem = new PictureviewerInfoItem(fi.fileName());
+	QRectF infoItemRect = infoItem->boundingRect();
+	int infoWidth = infoItemRect.size().width();
+	int viewportWidth = viewport()->size().width();
+	int center = (viewportWidth - infoWidth) / 2;
+	mInfoItem = infoItem;
+	QPoint infoPoint = QPoint(center, 10);
+	infoItem->setPos(infoPoint);
+	mScene->addItem(infoItem);
+}
+
+void PictureViewer::next(){
+	if(mCurrentEntry == mDirEntries.constEnd()){
+		return;
+	}
+	QString nextPath;
+	while(mCurrentEntry != mDirEntries.constEnd()){
+		++mCurrentEntry;
+		if(mCurrentEntry == mDirEntries.constEnd()){
+			break;
+		}
+		QFileInfo fi = *mCurrentEntry;
+		if(isPic(fi.absoluteFilePath())){
+			nextPath = fi.absoluteFilePath();
+			break;
+		}
+	}
+	if(!nextPath.isEmpty()){
+		showPic(nextPath);
+	}
+}
+
+void PictureViewer::previous(){
+	if(mCurrentEntry == mDirEntries.constBegin()){
+		return;
+	}
+	QString nextPath;
+	while(mCurrentEntry != mDirEntries.constBegin()){
+		--mCurrentEntry;
+		QFileInfo fi = *mCurrentEntry;
+		if(isPic(fi.absoluteFilePath())){
+			nextPath = fi.absoluteFilePath();
+			break;
+		}
+	}
+	if(!nextPath.isEmpty()){
+		showPic(nextPath);
+	}
+}
+
+void PictureViewer::wheelEvent(QWheelEvent *event){
+	int steps = event->delta() / 8 / 15;
+	if(steps < 0){
+		next();
+	}else{
+		previous();
+	}
+}
+
+void PictureViewer::setGradient(){
+	QColor c1(255, 7, 15);
+	QColor c2(80, 55, 250);
+	QLinearGradient g(QPointF(0, 0), sceneRect().bottomRight());
+	g.setColorAt(0, c1);
+	g.setColorAt(1, c2);
+	setBackgroundBrush(QBrush(g));
+}
+
+void PictureViewer::setDir(const QString &path){
+	QFileInfo fi(path);
+	QString dir = fi.absolutePath();
+	if(dir == mCurrentDir || !fi.exists()){
+		return;
+	}
+	mCurrentDir = dir;
+	QDir currentDir = QDir(mCurrentDir);
+	mDirEntries = currentDir.entryInfoList(QDir::Files, QDir::Name);
+	std::sort(mDirEntries.begin(), mDirEntries.end(), Helper::SortFileInfoList());
+	mCurrentEntry = std::find_if(mDirEntries.constBegin(), mDirEntries.constEnd(), std::bind2nd(Helper::FileInfoListContains(), fi.fileName()));
+}
+
+bool PictureViewer::isPic(const QString &path){
+	QFileInfo fi(path);
+	if(!fi.exists() || !fi.isFile()){
+		return false;
+	}
+	QString mime = Helper::mimeType(path);
+	if(mime.toLower().startsWith("image")){
+		return true;
+	}
+	return false;
+}
+
+QPointF PictureViewer::center(const QPixmap &pic){
+	QSize viewportSize = viewport()->size();
+	float x = (viewportSize.width() - pic.width()) / 2;
+	float y = (viewportSize.height() - pic.height()) / 2;
+	return QPointF(x, y);
+}