在构造函数中访问容器子窗口小部件的尺寸 [英] Accessing a container child widget dimensions in a constructor
问题描述
假设我有一个包含两个 Gtk :: Containers
的类,如下所示:
class示例:public Gtk :: VBox
{
public:
示例();
virtual〜Example();
私人:
Gtk :: HBox m_c1; //第一个容器
Gtk :: Grid m_c2; //第二个容器
};
构造一个示例
以这种方式实现:
示例:: Example()
{
const int nbRows {6};
const int nbColumns {7}; (int col {0}; col< nbColumns; ++ col)
$ )};
m_c1.pack_start(* btn); (int col {0}; col< b
{
}
(int row {0}; row< nbRows; ++ row) nbColumns; ++ col)
{
Gtk :: Button * btn {new Gtk :: Button(A)};
m_c2.attach(* btn,col,row,1,1);
}
}
//布局设置:
pack_start(m_c1);
pack_start(m_c2);
show_all();
}
我想要做的是确保<$ c中的子窗口小部件为了确保两个容器之间的视觉一致性,$ c> m_c2 与 m_c1
中的子构件大小相同。否则,它看起来像这样:
只是为了让当然,我不希望让 m_c1
成为 Gtk :: Grid
。
下面是我到目前为止所尝试的:我使用 Gtk :: HBox 中的
get_child_at() code>
m_c1
来获得对其第一个孩子的引用。然后,我在该子节点上调用 get_width()
和 get_height()
。这个想法是为这些维度提供 m_c2
的子窗口小部件。问题是返回的引用是 nullptr
。
从我读过的一些帖子看来,它似乎是我的小部件可能还没有实现,这将解释我的困难。我怎么能做到这一点?
您需要将网格中的每个按钮设置为水平扩展。然后所有的尺码都会自行处理。
Let's say I have a class with two Gtk::Containers
like so:
class Example : public Gtk::VBox
{
public:
Example();
virtual ~Example();
private:
Gtk::HBox m_c1; // First container
Gtk::Grid m_c2; // Second container
};
Constructing an Example
is implemented this way:
Example::Example()
{
const int nbRows{6};
const int nbColumns{7};
for(int col{0}; col < nbColumns; ++col)
{
Gtk::Button* btn {new Gtk::Button("A")};
m_c1.pack_start(*btn);
}
for(int row{0}; row < nbRows; ++row)
{
for(int col{0}; col < nbColumns; ++col)
{
Gtk::Button* btn {new Gtk::Button("A")};
m_c2.attach(*btn, col, row, 1, 1);
}
}
// Layout setup:
pack_start(m_c1);
pack_start(m_c2);
show_all();
}
What I want to do is to make sure the child widgets in m_c2
are the same size as the child widget in m_c1
, to ensure visual consistency between the two containers. Otherwise, it looks like this:
Just to make sure, I do not want m_c1
to be made a Gtk::Grid
.
Here's what I have tried so far: I used the get_child_at()
method available from the Gtk::HBox
m_c1
to get a reference to its first child. I then called get_width()
and get_height()
on that child. The idea was to feed m_c2
's child widgets these dimensions. The problem is that the returned reference is a nullptr
.
From some posts I have read, it seems my widgets may no yet be realized, and that would explain my difficulties. How could I achieve this?
You need to set each button in the grid to expand horizontally. Then all the sizing will take care of itself.
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