更换SpkWindow基类为QWidget并修复多个问题

修复mResizable为false时阻止窗口移动的问题
更改About窗口为固定大小

gui/spkabout.cpp

@@ -7,9 +7,12 @@ SpkAbout::SpkAbout(QWidget *parent) : SpkDialog(parent)
 {
   setWindowModality(Qt::ApplicationModal);
 
-  mDialogWidget->setMaximumWidth(600);
+//  mDialogWidget->setMaximumWidth(600);
   mDialogWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
+  setFixedSize(550, 450);
+  SetResizable(false); // Do you like the dilemma of using self created widget?
+
   mIconLay = new QHBoxLayout;
 
   mSpkVersion = new QLabel;
@@ -24,25 +27,31 @@ SpkAbout::SpkAbout(QWidget *parent) : SpkDialog(parent)
   mSpkIcon = new QLabel;
   mSpkIcon->setPixmap(QIcon(":/icons/spark-store.svg").pixmap(QSize(128, 128)));
 
-  auto description =
+  auto description = tr(
       "Spark Store was started when Chinese home-grown Linux operating systems "
       "had initially hit the market. Because the Linux desktop ecosystem is not "
       "good enough at the time being, volunteers built this small App Store in "
       "the hope that users can get useful applications faster.\n\n"
       "Right now we are not just a Chinese group. We are discovering our way into "
       "more Debian-based Linux OSes, and build a real community software repository "
-      "for users around the world.";
+      "for users around the world.");
   mDescriptionText = new QLabel;
   mDescriptionText->setObjectName("spk_about_desc");
   mDescriptionText->setWordWrap(true);
   mDescriptionText->setText(description);
 
+  mIconLay->addStretch(3);
   mIconLay->addWidget(mSpkIcon);
+  mIconLay->addStretch(1);
   mIconLay->addWidget(mSpkVersion);
-  mIconLay->setAlignment(Qt::AlignVCenter);
+  mIconLay->addStretch(3);
+  mIconLay->setAlignment(Qt::AlignVCenter | Qt::AlignHCenter);
+
+  AddStretch();
   AddLayout(mIconLay);
   AddSpacing(18);
   AddWidget(mDescriptionText);
+  AddStretch();
   SetMargin(18, 0, 18, 18);
 
   GetTitleBar()->SetOperationButton(SpkTitleBar::OperationButton::Close);