Time-line for time intervals

Question

I search for a command that do something like this: I can enter two time intervals: the first is the total length of the time-line, and the second is the period to be highlighted. For example the following command:

\timeline{1900-2000}{1950}{2000}

produce something like this:

Another example:

\timeline{1900-2000}{1925}{1965}

---

Optionally I can print the years (for example with the * symbol):

\timeline{*1900-*2000}{*1945}{1976}

If I want to print all the years, I can enter both the following commands:

\timeline{*1900-*2000}{*1950}{*2000}
\timeline[*]{1900-2000}{1950}{2000}

Another example:

\timelineyears[*]{1900-2000}{1925}{1965}

---

If I want I can enter an inexact year (for example with the ~ symbol), that produce a colour gradient in the direction of that year. Example:

\timelineyears{1900-2000}{1945}{~1976}

\timelineyears{1900-2000}{~1945}{1976}

\timelineyears{1900-2000}{~1945}{~1976}

(Perhaps, if I enter an inexact year and I print it, it is better to differentiate it in some way respect to the exact years.)

---

I can also set the time interval:

\settimeinterval{1900-2000}

in this way I have only to specify the range to highlight:

\timeline{1912}{1920}

The time interval remains the same until the next \settimeinterval declaration (but I can overwrite it with the default command \timeline{a-b}{c}{d}).

Answer 1

The command is structured as follows

\Timeline[ <option> ]{ <start>-<end> }{ <startint> }{ <endint> }

Adding * to the option will print all the years, otherwise, none will be printed. The first argument <start>-<end> will set the beginning and the end year respectively. The last two arguments set the interval. Adding ~ before the year will activate the gradient effect.

With the help of David Carlisle the tilde has been fixed. Now it will appear when you add a year that's supposed to be inexact.

Output (various)

Code

\documentclass[margin=10pt]{standalone}
\usepackage{tikz}
\usepackage{xstring}
\usepackage[T1]{fontenc}
\usepackage{newtxtext}

\usetikzlibrary{fadings}

\newcommand\Timeline[4][]{%
    % Some options
    \def\printy{*}
    \def\option{#1}
    % Setting Start-End bar
    \StrBehind{#2}{-}[\endyear]
    \StrBefore{#2}{-}[\startyear]
    % Setting Start-End Interval
    \StrRight{#3}{4}[\startint]
    \StrRight{#4}{4}[\endint]
    % Some calculations
    \pgfmathsetmacro\endy{(\endyear-\startyear)/10}
    \pgfmathsetmacro\fromyear{(\startint-\startyear)/10}
    \pgfmathsetmacro\toyear{(\endint-\startyear)/10}
    \pgfmathsetmacro\midy{(\fromyear+\toyear)/2}
    % Fill interval
    \fill (\fromyear,0) rectangle (\toyear,.2);
    % Fill with gradient if ~ is added
    \IfSubStr{#3}{~}{%
        \fill[right color=black, left color=white] (\fromyear,0) rectangle (\midy,.2);
        \node[anchor=north] at (\fromyear,0) {\string~\phantom{#3}};
        }{}
    \IfSubStr{#4}{~}{%
        \fill[right color=white, left color=black] (\midy,0) rectangle (\toyear,.2);
        \node[anchor=north] at (\toyear,0) {\string~\phantom{#4}};
        }{}
    \draw[white] (\fromyear,0) rectangle (\toyear,.2);
    % Print years
    \ifx\option\printy\relax
    \node[anchor=north] at (0,0) {\startyear};
    \node[anchor=north] at (\endy,0) {\endyear};
    \node[anchor=north] at (\fromyear,0) {#3};
    \node[anchor=north] at (\toyear,0) {#4};
    \fi
    % Print rectangle
    \draw (0,0) rectangle (\endy,.2);
}

\begin{document}
\begin{tikzpicture}

\Timeline[*]{1900-2000}{~1950}{1974}
\end{tikzpicture}
\end{document}