On MacOS, a "wish" application started from the terminal opens in the
background, thus doesn't match user expectation that a newly-launched
application ought to be placed in the foreground. To address this
shortcoming, both gitk and git-gui use Apple Events to send a message to
"System Events" instructing it to foreground the "wish" application by
PID.

Unfortunately, MacOS 10.14 tightens restrictions on Apple Events,
requiring explicit granting of permission to control applications in
this fashion, and apparently such granting for "Automation" is not
allowed at all[1]. As a consequence gitk crashes outright at launch time
with a "Not authorized to send Apple events to System Events" error,
thus is entirely unusable on "Mojave".

In contrast, git-gui does not crash since it deliberately[2] catches and
ignores Apple Events errors. This does mean that git-gui will not
automatically become the foreground application on "Mojave", which is a
minor inconvenience but far better than crashing outright as gitk does.

Update gitk to catch and ignore Apple Events errors, mirroring git-gui's
behavior, to avoid this crash.

(Finding and implementing an alternate approach to foregrounding the
"wish" application on "Mojave" may be desirable but is outside the scope
of this crash fix.)

[1]: https://lore.kernel.org/git/D295145E-7596-4409-9681-D8ADBB9EBB0C@me.com/
[2]: https://lore.kernel.org/git/CABNJ2G+h3zh+=wLA0KHjUn8TsfhqUK1Kn-1_=6hnXVRJUPhuuA@mail.gmail.com/

Reported-by: Evgeny Cherpak <cherpake@me.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>

gitk uses classic (non-themed) spinboxes rather than the ttk variants.
Commit d93f171 ("gitk: Use themed tk widgets", 2009-04-17) that added
ttk makes no mention of why ttk:spinboxes were omitted, but this leads
to an inconsistent interface. Let's use the ttk version.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk's 'Commit ID' button uses a classic widget, not a themed one,
leading to inconsistent style. Commit 51a7e8b (d93f171 ("gitk: Use
themed tk widgets", 2009-04-17) that added themed widgets did not touch
this particular widget, but does not say why. Regardless, let's use a
themed button to be consistent with the rest of the interface.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk uses themed tk, but has no capability to alter the theme defined
by Tk. While there are documented ways to install other themes, and
to make one the default, these methods are obscure at best. Instead,
let's offer two config variables:

- theme  this is the name of the theme to use, and must be available.
- themeloader - this is the full pathname of a tcl script that
  will load one or more themes into the Tk namespace.

By default, theme is set to the theme active when Tk is started, and
themeloader = {}.  These variables must be defined to something else to
have any user visible effect.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk uses themed widgets with a user selected theme, but also invokes
tk_setPalette to configure colors for the non-themed widgets including
the menubar. However, themes in general are expected to configure
those colors already. The builtin themes (default, alt, clam, classic on
unix/X11) all have compatible colors, and need no such reconfiguration,
and (most, if not all) available themes set the options database for this
purpose as well. Furthermore, gitk in the past avoided invoking
tk_setPalette on Windows to avoid some issues.

So, let's stop calling tk_setPalette everywhere, and just rely upon the
selected theme (possibly user installed) to have set all needed colors.

Note: if a user installs more than one theme using $themeloader, the last
one installed will have defined the colors to be used. Those colors will
probably be incorrect for any other set, including Tk's builtin set.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk maintains a stack of commit ids visited, and allows navigating
these using a pair of buttons shown with arrows using bitmaps. An attempt
is made to recolor these bitmaps to handle different color schemes, but
this is unreliable across multiple themes as the required colors are not
universally known. Let's just use text labels for these buttons,
allowing the themes to recolor the text along with everything else. Use
utf code points for the text, presuming that these arrow glyphs are
available in the selected font.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk allows searching for commits with various criteria, and provides
up/down search buttons to facilitate this search. These buttons are
labelled with bitmaps, and those bitmaps are not always recolored
correctly for the ui scheme as the theme colors are not known. Let's
just use text labels on these, allowing the styles to handle any
coloring needed. Use utf codepoints for the arrows, presuming that these
code points are available in the selected font.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk offers to change the ui color on the colors prefs page, but the
variable set has no effect because gitk is using themes. Let's eliminate
the "Interface" color selection option from that page.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk has a number of variables used in setting up colors for the classic
(non-themed) widget set. These variables are unused with ttk, so let's
eliminate them. But, leave the variables in the config file for now -
those can be eliminated after this change is merged.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk currently accepts a single themeloader file via the config file,
and will source this with errors reported to the console. This is fine
for simple configuration, but will not support interactive theme
exploration from the gui. In particular, a themeloader file must be
sourced only once as the themes defined cannot be re-defined. Also,
errors must be handled rather than just aborting while printing to the
console.  So, add a proc to handle the above, supporting expansion of
the gui config pages.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk allows configuring a particular theme in its configuration file
(default on linux: ~/.config/git/gitk), but offers no ability to modify
this from gitk's configuration editor. Let's add this to the color
configuration page.

Present the offered themes in a list, and allow choosing / modifying a
theme definition file ($themeloader). Update the list of themes if the
theme file is modified, and update the theme if specifically requested
(by default, just change the value for use after gitk is restarted).

Any theme definition file can change the global options database,
affecting potentially any theme. So, the ultimate configuration should
have either
- no theme definition file (themeloader = {}), and a native Tk, theme,
or
- themeloader naming a valid file, and $theme naming a theme defined by
  that file.

But, there is no trivial way to enforce the above. Shrug.

Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

* mr/sort-refs-by-type:
  gitk: fix error when remote tracking branch is deleted

* es/ignore-osascript-failure:
  gitk: fix MacOS 10.14 "Mojave" crash on launch

gitk's configuration dialog can be resized, but this does not expand the
space allocated to any widgets. Some items may have long lines of text
that would be visible if the widgets expanded, but this does not happen.

The top-level container uses a two column grid and allocates any space
change equally to both columns.  However, the configuration pages are
contained in one cell so half the additional space is wasted if
expanding. Also, the individual configuration pages do not mark any
column or widgets to expand, so any additional space given is just used
as padding.

Collapse the top-level page to have one column, placing the "OK" and
"Cancel" buttons in a non-resizing frame in column 1 (this keeps the
buttons in constant geometry as the dialog is expanded). This makes all
additional space go to the configuration page.

Mark column 3 of the individual pages to get all additional space, and
mark the text widgets in that column so they will expand to use the
space. While we're at it, eliminate or simplify use of frames to contain
column 2 content, and harmonize the indents of that content.

prefspage_general adds a special "spacer" label in row 2, column 1, that
causes all of the subsequent rows with no column 1 content to indent,
and this carries over to the next notebook tab (prefspage_color) through
some undocumented feature. The fonts page has a different indent, again
for unknown reason. The documented approach would be to use -padx
explicitly on all the rows to set the indents.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk's configuration dialog uses a large number of widgets, and this
code is hard to read as there is no easily recognizable grouping or
breaks. Help this by adding space between items that occupy a single row
in the dialog.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

gitk sets no size limit on its configuration dialog, allowing the user
to collapse the window so almost nothing is visible. The geometry
manager sets an initial size so all the widgets are visible, though
ignores the potentially very long text in the entry widgets in doing so.
Let's use this initial size as the minimum. The size information is
computed in Tk's idle processing queue, so a wait is required.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

* ml/themes:
  gitk: set minimum size on configuration dialog
  gitk: separate code blocks for configuration dialog
  gitk: make configuration dialog resizing useful
  gitk: add theme selection to color configuration page
  gitk: add proc run_themeloader
  gitk: eliminate unused ui color variables
  gitk: eliminate Interface color option from gui
  gitk: use text labels for next/prev search buttons
  gitk: use text labels for commit ID buttons
  gitk: do not invoke tk_setPalette
  gitk: use config variables to define and load a theme
  gitk: make sha1but a ttk::button
  gitk: use themed spinboxes

Signed-off-by: Johannes Sixt <j6t@kdbg.org>

* 'master' of https://github.com/j6t/gitk:
  gitk: set minimum size on configuration dialog
  gitk: separate code blocks for configuration dialog
  gitk: make configuration dialog resizing useful
  gitk: add theme selection to color configuration page
  gitk: add proc run_themeloader
  gitk: eliminate unused ui color variables
  gitk: eliminate Interface color option from gui
  gitk: use text labels for next/prev search buttons
  gitk: use text labels for commit ID buttons
  gitk: do not invoke tk_setPalette
  gitk: use config variables to define and load a theme
  gitk: make sha1but a ttk::button
  gitk: use themed spinboxes
  gitk: fix MacOS 10.14 "Mojave" crash on launch
  gitk: fix error when remote tracking branch is deleted