I have a GtkTextView, and I would like to be able to set a maximum line width for the text. If the width of the TextView exceeds the maximum text width, the extra space should be filled with padding on the left and right on the text. Although Gtk supports a min-width CSS property, there appears to be no max-width property. Instead I tried to dynamically set the margins whenever the TextView is resized by connecting size-allocate to
def on_textview_size_allocate(textview, allocation):
width = allocation.width
if width > max_width:
textview.set_left_margin((width - max_width) / 2)
textview.set_right_margin((width - max_width) / 2)
else:
textview.set_left_margin(0)
textview.set_right_margin(0)
This produces the desired text line width for any given TextView width, but leads to strange behavior when resizing the window. Resizing the window to a smaller width happens with a slow delay. Attempting to maximize the window makes the window jump to a width much larger than the screen. size-allocate may not be the correct signal to connect to, but I have not been able to find any other way to dynamically set margins when the TextView is resized.
What is the correct way to achieve a maximum text line width?
I came up with a solution. I created a custom container by inheriting from GtkBin, overrode do_size_allocate, and added my GtkTextView to that container:
class MyContainer(Gtk.Bin):
max_width = 500
def do_size_allocate(self, allocation):
# if container width exceeds max width
if allocation.width > self.max_width:
# calculate extra space
extra_space = allocation.width - self.max_width
# subtract extra space from allocation width
allocation.width -= extra_space
# move allocation to the right so that it is centered
allocation.x += extra_space / 2
# run GtkBin's normal do_size_allocate
Gtk.Bin.do_size_allocate(self, allocation)
Related
Can someone help me in understanding how to calculate the Height and Width of a Powershell Forms. For Example I Created a blank Powershell form of Height 500 and Width 700 and now If want to place a Text box a little below from the top of the form what will be the height and width that I need to enter? and If I want to place a Button at middle of the Form? what will be the height and width that I need to enter? I am struggling with this calculation.
You should get the screen size and use the ratio to set position. The ratio is useful for different screen size.
I am implementing a container which algins its children in a row and does kind of a linebreak when there is no horizontal space left. Thus, the required height depends on the available width. For larger widths, more content fits in one line and less lines are needed leading to less height. For smaller widths, less content fits in one line and more height is needed.
I subclassed the container and implemented the needed logic. The minimum width of the container is set to the minimum width of the widest child which would display one extreme case where there are stacked lines, some of them with only a single child inside them.
The problem is as follows: The window displaying the container has a very large height, for some cases even larger than my monitor. I am able to resize the window except that I cannot decrease the width. It turns out that the documentation for height-for width geometry management says:
Next, the toplevel will use the minimum width to query for the minimum height contextual to that width using gtk_widget_get_preferred_height_for_width()[...]. The minimum height for the minimum width is normally used to set the minimum size constraint on the toplevel (unless gtk_window_set_geometry_hints() is explicitly used instead).
Thus, the behaviour is expected as the window uses the height for the minimum width as its minimum height leading to the previously mentioned extreme case. This seems to be counterintuitive as in my case and an example used in the documentation (textflow in labels) the height will be maximal when the width is minimal vice versa. Only when actually allocating the available space, gtk considers to assign smaller heights when a larger width allows that. Even when using high widths in the window's default size and size request only the minimum width of the container is considered to derive the required height of the window.
The documentation already somehow contains a workaround, namely the geometry hints. But this seems to be a verbose and static way of sizing the window when the default width of the window together with the height-for-width-function could theoretically be used to easily determine the size of everything. The size-allocation already works as intended, only the size-negotiation cancels the benefits the height-for-width function could bring here. Is there any nice way of implementing the functionality required to fix the window sizing?
It seems as there is no intended workaround for this problem the way I searched for. The gtk size negotiation goes from bottom to top when requesting sizes and top to bottom when allocating. Thus, my container has no way of knowing how much width its parent could assign to it.
I solved the problem by adding a property which defines the minimum of children per row. This can be used to increase the minimum width and therefore decrease the minimum height. I only use it for the minimum width calculation while actually ignoring it doing the real size allocation which only is a minor detail I will document.
This documentation will be part of the code example I will provide as an answer to my old post which was about implementing a FlowBox with the behaviour described above.
Is there a way to change the height of a text field on the whole figure without changing the x and y position?
To change we must use the position, which requires to change the coordinates. I would like to change only the height, without changing x and y.
Just store the current x and y, and use those in your set call like so:
old_pos = get(text_field_handle,'Position');
set(text_field_handle,'Position',[old_pos(1:2),new_width,new_height]);
Well, you can change the FontSize property, this won't change the coordinates, but will increase width as well as height. See Text Properties in the doc for more details.
I am assuming you are working with uicontrol('style','text').
From the uicontrol properties you have:
Position
position rectangle
*Size and location of uicontrol*. The rectangle defined by this property
specifies the size and location of the control within the parent figure
window, uipanel, or uibuttongroup. Specify Position as:
[left bottom width height]
where left and bottom define the distance from the lower-left corner of the
container to the lower-left corner of the rectangle. width and height are the
dimensions of the uicontrol rectangle.
You can then just change the width and height keeping the original left and bottom.
One can set the Margin property of a text object to increase the height of the object without changing the fontsize, but this influences both the height and the width of the text object. I am not sure what it means to make the height smaller than what Matlab thinks is the text height, so I will assume you are interested in increasing the size.
Increasing the height of the text object is relatively easy if you are willing to use the LaTeX interpreter. You just need to add an "empty" box of whatever height you want:
text(0.5, 0.25, 'Hello World\parbox{\textwidth}{\vspace{1in}}', 'Interpreter', 'LaTeX', 'BackgroundColor',[1, 0, 0]);
This won't increase the height by exactly 1 inch, instead it will be more like 1 inch minus a baseline skip. Determining the actual height increase in displayed units adds even more problems. You might be able to change the height with unicode characters, and hence skip the LaTeX interpreter, but I have no idea how.
I need to render a TextArea in an exact pixel width for the special purposes of my GUI.
When I set its width to "250px", it comes out as 256px.
Is there a way to override this behavior so I can render it as 250px exactly?
When you use setWidth(), you're effectively setting the element's content width.
To get the offset width use UIObject#getOffsetWidth(). This will return the width including padding and border (but not margins).
References on W3C
Computing widths and margins
The box model
Forms on Windows 7 and Vista have thicker borders than those of XP. As a result, some content that spans the entire height or width of a form will be cut off. Is there a simple way to fix this, or do all the forms of my application need to be resized to accommodate for this?
Update: It appears to be the fault of the form size and not the borders that are causing the problem. See the following images for an example. Notice how the controls have the correct location at the top-right corners, but they reach the each of the form in Windows 7 while a border is retained in XP. The same code is used to resize and position the controls.
Here's what a form looks like in XP:
alt text http://img504.yfrog.com/img504/1328/bordersxp.png
You should fix the size of the form programatically, to make sure the client size is big enough to fit everything. You can easily calculate the difference between the current size and client size of the form, and increase/decrease by the right amount.
You probably want to perform this inside Form_Load.
In VB6, the client size and width are referred to as ScaleWidth and ScaleHeight for forms. Setting these values just messes up the scaling, rather than resizing the form, so you instead have to do calculations so you can set the normal Width and Height properties.
BorderSize = Me.Width - Me.ScaleWidth
Me.Width = BorderSize + CorrectScaleWidth
//Same for height!