import sys, math
import PyQt5.QtCore as QtCore
import PyQt5.QtWidgets as QtWidgets
import PyQt5.QtGui as QtGui


# ---------------------------------------------------------------------------------------------------------
class clsFilePreviewModel(QtWidgets.QFileSystemModel):
  def __init__(self, cacheWidth=100, cacheHeight=100):
    super().__init__()
    self.previews = {'None': None}
    self.cacheWidth = cacheWidth
    self.cacheHeight = cacheHeight
    self.ncols = 2

  #----------------------------------------------------------------------------
  def getPreview(self, index):
    itemName = super().data(index, QtCore.Qt.DisplayRole)

    if itemName not in self.previews:
      qpm = QtGui.QPixmap(self.rootPath() + "/" + itemName)

      if qpm is None or qpm.isNull():
        qpm = super().data(index, QtCore.Qt.DecorationRole)
        if qpm and not qpm.isNull():
          qpm = qpm.pixmap(self.cacheWidth, self.cacheHeight)
      if qpm and not qpm.isNull():
        qpm = qpm.scaled(self.cacheWidth, self.cacheHeight, QtCore.Qt.KeepAspectRatio)

      self.previews[itemName] = qpm
    return self.previews[itemName]

  # ----------------------------------------------------------------------------
  def data(self, index, role):
    if role == QtCore.Qt.DecorationRole:
      return self.getPreview(index)
    else:
      return super().data(index, role)

# ---------------------------------------------------------------------------------------------------------
class clsIconsGrid(QtWidgets.QWidget):
  def __init__(self, dir_path):
    super().__init__()

    self.gridSize = QtCore.QSize(200,200)

    self.path = dir_path
    self.files = clsFilePreviewModel()
    self.files.setRootPath(self.path)

    self.view = QtWidgets.QListView()
    self.view.setModel(self.files)
    self.view.setRootIndex(self.files.index(dir_path))
    self.view.setViewMode(QtWidgets.QListView.IconMode)
    self.view.setGridSize(self.gridSize)

    layout = QtWidgets.QHBoxLayout()
    layout.addWidget(self.view)
    self.setLayout(layout)