如何使用 qtruby 让 model/view 为 table 工作?

how to get model/view working for table using qtruby?

我正在尝试弄清楚如何将 TableView 与使用 qtruby 的模型一起使用。我试图在给出的教程中修改 C++ 中的示例 http://doc.qt.io/qt-5/modelview.html 并想出了如下所示的代码。

问题出在AbstractTableModel的数据方法的实现上:只有角色Qt::DisplayRole按预期工作。角色 Qt::FontRole 和 Qt::BackgroundRole 不会导致错误,但似乎也没有做任何事情。更糟糕的是,角色 Qt::TextAlignmentRole 和 Qt::CheckStateRole 如果启用会导致分段错误。如果我在这里做错了什么,有人可以告诉我吗?

#!/usr/bin/env ruby
require 'Qt'
include Qt

class MyModel < AbstractTableModel
  def initialize(p)
    super
  end

  def rowCount(p)
    2
  end

  def columnCount(p)
    3
  end

  def data(index, role)
    row = index.row
    col = index.column

    case role
    when Qt::DisplayRole
      return Variant.new "Row#{row + 1}, Column#{col + 1}"
    when Qt::FontRole
      # this doesn't result in an error, but doesn't seem to do anything either
      if (row == 0 && col == 0)
        boldFont = Font.new
        boldFont.setBold(true)
        return boldFont
      end
    when Qt::BackgroundRole
      # this doesn't result in an error, but doesn't seem to do anything either
      if (row == 1 && col == 2)
        redBackground = Brush.new(Qt::red)
        return redBackground
      end
    when Qt::TextAlignmentRole
      # # the following causes a segmentation fault if uncommented
      # if (row == 1 && col == 1)
      #   return Qt::AlignRight + Qt::AlignVCenter
      # end
    when Qt::CheckStateRole
      # # the following causes a segmentation fault if uncommented
      # if (row == 1 && col == 0)
      #   return Qt::Checked
      # end
    end
    Variant.new
  end
end

app = Application.new ARGV
tableView = TableView.new
myModel = MyModel.new(nil)
tableView.setModel(myModel)
tableView.show
app.exec

这是因为您正在按预期为 DisplayRole 创建新的 Qt::Variant。

对于其他 return 值,您应该使用:

return Qt::Variant.fromValue(boldFont)

return Qt::Variant.fromValue(redBackground)

return Qt::Variant.fromValue(Qt::AlignRight + Qt::AlignVCenter)

return Qt::Variant.fromValue(Qt::Checked)