Leading newlines are stripped from code segments

[spirali]

Leading newlines are stripped from code segments

[spirali]

I have implemented "priority" for text styles that may help with your use case. PR #82 allows to run the following code (It is draft and now runs only in Inkscape mode, not Cairo mode):

    b = slide.box()
    b.set_style("grayout", TextStyle(color="gray", priority=1))  # <---- priority=1 is NEW
    b.code(
        "c",
        """~grayout{#include <stdio.h>
/* Hello world program */

int ~#A{main}() {}
    printf("Hello ~emph{world!\\n");}
    return 0;
}""",

That should look like this:

Is it ok for you?

[spirali]

It is done slightly on purpose. Can you share your use case? It cannot be switched off in the current version. But is like 3 lines of code to add this option. I will do it if it helps you.

[tylerjw]

Here is the function I wrote where I discovered this effect:

def grayed_before_after_code_slide(
    parent: Box,
    title: str,
    language: str,
    code: str,
    code_start: int,
    code_lines: int,
):
    code_bg = "#F6F8FA"
    box = parent.box(y=0, width="100%", height="100%", p_bottom=20, z_level=-2)
    box.rect(bg_color=code_bg, rx=20, ry=20)
    overlay = box.overlay()
    (before, code) = split_lines(code, code_start)
    (code, after) = split_lines(code, code_lines)
    before_box = overlay.sbox(
        name="before", x=0, y=0, p_left=20, p_right=20, p_top=20, p_bottom=20, z_level=0
    )
    before_box.code("", before, style="grayed")
    code_box = overlay.sbox(
        name="code", x=0, y=before_box.y("100%"), z_level=0, p_left=20, p_right=20
    )
    code_box.code(language, code)
    after_box = overlay.sbox(
        name="after", x=0, y=code_box.y("100%"), z_level=0, p_left=20, p_right=20
    )
    after_box.code("", after, style="grayed")

What I'm doing here is graying out code before and after some lines as a way of highlighting the lines I want to show in a larger context. I discovered that depending on where I split it will remove a newline.

Here is an example of calling this function:

@slides.slide(debug_boxes=False)
def details(slide):
    grayed_before_after_code_slide(
        slide,
        "ParameterDescriptor",
        "C++",
        """  auto param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Mine!";
  param_desc.additional_constraints  = "One of [world, base, home]";
  params.my_string = node->declare_parameter("my_string",
    params.my_string, param_desc);

  param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Who controls the universe?";
  param_desc.additional_constraints  = "A multiple of 23";
  params.my_number = node->declare_parameter("my_number",
    params.my_number, param_desc);
  // ...
""",
        6,
        5,
    )

And here is the resulting slide:

I presume the reason for this functionality is that you want the """ on one line with the code starting on the next without the newline showing up in your slide.

I've played around with implementing my function just using text and the grayed style instead of the code tag and have not yet gotten it to do what I want because I need the middle section to have syntax highlighting.

[tylerjw]

On the above code, here is a slight variation where I highlight the line before the line break and it is preserved:

@slides.slide(debug_boxes=False)
def details(slide):
    grayed_before_after_code_slide(
        slide,
        "ParameterDescriptor",
        "C++",
        """  auto param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Mine!";
  param_desc.additional_constraints  = "One of [world, base, home]";
  params.my_string = node->declare_parameter("my_string",
    params.my_string, param_desc);

  param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Who controls the universe?";
  param_desc.additional_constraints  = "A multiple of 23";
  params.my_number = node->declare_parameter("my_number",
    params.my_number, param_desc);
  // ...
""",
        4,
        6,
    )

[tylerjw]

Thank you for this. I'll try this out this weekend and see if I can make it work for my use-case. Thank you for your amazing work on this library.

[tylerjw]

I tried getting this to work for me but I can't seem to reproduce the behavior from the PR. I checked out the repo and installed it into my python virtual env with pip install .. When I try to set the priority flag and then use the style in the code function it does not seem to work:

.code(
            "C++",
            """~grayout{  auto param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Mine!";
  param_desc.additional_constraints  = "One of [world, base, home]";
  params.my_string = node->declare_parameter("my_string",
    params.my_string, param_desc); }
  param_desc  = rcl_interfaces::msg::ParameterDescriptor{};
  param_desc.description = "Who controls the universe?";
  param_desc.additional_constraints  = "A multiple of 23";
  params.my_number = node->declare_parameter("my_number",
    params.my_number, param_desc);
  // ...
""",
        )

[tylerjw]

In case you want my full slides source they are here: https://github.com/tylerjw/tylerjw.dev/tree/main/slides

I'm presenting at roscon this week and both my main talk and my lighting talk I've put together with your tool.

[spirali]

I will look at it during the day more carefully. Did you try the branch "priority" (not the main branch)?.

[tylerjw]

Yes, I think I did. I installed it into a virtual environment.

[spirali]

Oh, this is my mistake. You need to enable use_styles=True. I accidently did not pasted the last line of my example:

    b.set_style("grayout", TextStyle(color="gray", priority=1))
    b.code(
        "c",
        """~grayout{#include <stdio.h>
/* Hello world program */

int ~#A{main}() {}
    printf("Hello ~emph{world!\\n");}
    return 0;
}""",
    use_styles=True)  # <----- THIS

[spirali]

This is necessary because by default .code does not parse user styles (to not clash with programming language)