cherry-picking-a-pull-request.bx

from cupid.svgfig import SvgFig

COMMITW = 45
COMMITGAP = 25
COMMITSTRIDE = COMMITW + COMMITGAP
MARGIN = 10
STROKE = 1.5

class Branch:
    def __init__(self, fig, x, y, pod=None):
        self.fig = fig
        self.curx = x
        self.cury = y
        self.head = pod

    def commit(self, name=None, **kwargs):
        circle_args = dict(
            center=(self.curx, self.cury),
            size=(COMMITW, COMMITW),
            stroke_width=STROKE,
            )
        circle_args.update(kwargs)
        if name:
            circle_args.update(text=name)
        c = self.fig.circle(**circle_args)
        if self.head:
            self.fig.connect(self.head.east, 0, c.west, 0)
        self.head = c
        self.curx += COMMITSTRIDE
        return c

    def merge(self, other, name, **kwargs):
        y = min(self.cury, other.cury)
        circle_args = dict(
            center=(self.curx, y),
            size=(COMMITW, COMMITW),
            stroke_width=STROKE
            )
        circle_args.update(kwargs)
        c = self.fig.circle(**circle_args, text=name)
        self.fig.connect(self.head.east, 0, c.west, 0)
        self.fig.connect(other.head.east, 0, c.south, 270)
        self.head = c
        self.curx += COMMITSTRIDE
        return c

class GitFig(SvgFig):
    def __init__(self, nbranches, ncommits, **kwargs):
        figw = (ncommits * COMMITW) + ((ncommits - 1) * COMMITGAP) + 2 * MARGIN
        figh = (nbranches * COMMITW) + ((nbranches - 1) * COMMITGAP) + 2 * MARGIN
        super().__init__(size=(figw, figh), **kwargs)
        self.curx = MARGIN + COMMITW / 2

    def branch(self, name, y, pod=None, advance=0):
        y = MARGIN + COMMITW / 2 + y * COMMITSTRIDE
        if pod is None:
            x = self.curx + COMMITSTRIDE * advance
        else:
            x = pod.cx + COMMITSTRIDE * advance
        return Branch(self, x, y, pod=pod)

figsvgs = []

MASTER_KWARGS = dict(class_="blue tint", fill="#ddf")
BRANCH_KWARGS = dict(class_="green tint", fill="#cfc")
RELEASE_KWARGS = dict(class_="red tint", fill="#fdd")
NEW_KWARGS = dict(class_="yellow tint", fill="#ffc")
MERGECOMMIT_KWARGS = dict(stroke_width=STROKE+1.5)

def base_fig(branchkwargs={}, pr=True, release=False):
    global fig, main, pr1, relbranch
    nbranches = 1
    if release:
        nbranches += 1
        mainy = 1
    else:
        mainy = 0
    if pr:
        nbranches += 1
    fig = GitFig(nbranches=nbranches, ncommits=7)
    main = fig.branch("main", y=mainy)
    m1 = main.commit("A", **MASTER_KWARGS)
    m2 = main.commit("B", **MASTER_KWARGS)
    main.commit("C", **MASTER_KWARGS)
    main.commit("D", **MASTER_KWARGS)
    main.commit("E", **MASTER_KWARGS)
    if pr:
        pr1 = fig.branch("pr1", pod=m2, advance=1.5, y=mainy+1)
        pr1.commit("F", **BRANCH_KWARGS, **branchkwargs)
        pr1.commit("G", **BRANCH_KWARGS, **branchkwargs)
    if release:
        relbranch = fig.branch("release", pod=m1, advance=1, y=0)
        relbranch.commit("R", **RELEASE_KWARGS)
        relbranch.commit("S", **RELEASE_KWARGS)

def finish_figure(fig):
    cog.outl(fig.tostring())


# Figure 1:
base_fig()
finish_figure(fig)

# Figure 2:
base_fig()
main.merge(pr1, name="M", **NEW_KWARGS)
finish_figure(fig)

# Figure 3:
base_fig(branchkwargs={"stroke_dasharray": "4"})
main.commit("Fr", **NEW_KWARGS)
main.commit("Gr", **NEW_KWARGS)
finish_figure(fig)

# Figure 4:
base_fig(branchkwargs={"stroke_dasharray": "4"})
main.commit("FGs", **NEW_KWARGS)
finish_figure(fig)

# Figure 5:
base_fig(release=True, pr=False)
relbranch.commit("Ec", **NEW_KWARGS)
finish_figure(fig)

# Figure 6:
base_fig(release=True)
main.merge(pr1, name="M", **NEW_KWARGS, **MERGECOMMIT_KWARGS)
relbranch.commit("Fc", **NEW_KWARGS)
relbranch.commit("Gc", **NEW_KWARGS)
finish_figure(fig)

# Figure 7:
base_fig(branchkwargs={"stroke_dasharray": "4"}, release=True)
main.commit("Fr", **NEW_KWARGS)
main.commit("Gr", **NEW_KWARGS, **MERGECOMMIT_KWARGS)
relbranch.commit("Frc", **NEW_KWARGS)
relbranch.commit("Grc", **NEW_KWARGS)
finish_figure(fig)

# Figure 8:
base_fig(branchkwargs={"stroke_dasharray": "4"}, release=True)
main.commit("FGs", **NEW_KWARGS, **MERGECOMMIT_KWARGS)
relbranch.commit("FGsc", **NEW_KWARGS)
finish_figure(fig)