实现应用列表和SpkResource

SpkResource现有已知问题：首次使用不会完全进行所有任务。

gui/spkstretchlayout.cpp

@@ -0,0 +1,84 @@
+
+#include "spkstretchlayout.h"
+
+SpkStretchLayout::SpkStretchLayout(QWidget *parent) : QLayout(parent)
+{
+}
+
+SpkStretchLayout::~SpkStretchLayout()
+{
+  QLayoutItem *item;
+  while((item = takeAt(0)))
+    delete item;
+}
+
+void SpkStretchLayout::addItem(QLayoutItem *item)
+{
+  mItems.append(item);
+}
+
+QSize SpkStretchLayout::sizeHint() const
+{
+  int n = mItems.count();
+  auto minSize = mItems.isEmpty() ? QSize { 0, 0 } : mItems.first()->minimumSize();
+  QSize s { 200, 50 }; // s: Hint
+  if(n)
+    s = s.expandedTo(QSize { minSize.width(), minSize.height() * n });
+  return s + n * QSize(spacing(), spacing());
+}
+
+QSize SpkStretchLayout::minimumSize() const
+{
+  int n = mItems.count();
+  auto minSize = mItems.isEmpty() ? QSize { 0, 0 } : mItems.first()->minimumSize();
+  QSize s(minSize.width(), minSize.height() * n);
+  return s + n * QSize(spacing(), spacing());
+
+}
+
+int SpkStretchLayout::count() const
+{
+  return mItems.size();
+}
+
+QLayoutItem *SpkStretchLayout::itemAt(int i) const
+{
+  return mItems.value(i);
+}
+
+QLayoutItem *SpkStretchLayout::takeAt(int i)
+{
+  return i >=0 && i < mItems.size() ? mItems.takeAt(i) : nullptr;
+}
+
+void SpkStretchLayout::setGeometry(const QRect &rect)
+{
+  QLayout::setGeometry(rect);
+  if(mItems.isEmpty())
+    return;
+
+  int spc = spacing(), w = rect.width() - spc;
+  QSize size;
+  auto itm = mItems.first();
+
+  // All items are considered the same, so we only calculate with the first item.
+  // Figure out how many at most can we squeeze into one line
+  int countPerLine = w / (itm->minimumSize().width() + spacing());
+
+  if(countPerLine >= mItems.size()) // All items fit in one line
+    size = itm->minimumSize();
+  // Won't fit in one line.
+  else // Stretch items.
+    size = QSize {(w / countPerLine - spc), itm->maximumSize().height() };
+
+  QLayoutItem *o;
+  for(int i = 0; i < mItems.size(); i++)
+  {
+    o = mItems.at(i);
+    QRect geo;
+    geo.setSize(size);
+    geo.moveTo((i % countPerLine) * (size.width() + spc) + spc,
+               (i / countPerLine) * (size.height() + spacing()) + spc);
+    o->setGeometry(geo);
+  }
+}