st could easily tear/flicker with animation or other unattended
output. This commit eliminates most of the tear/flicker.
Before this commit, the display timing had two "modes":
- Interactively, st was waiting fixed `1000/xfps` ms after forwarding
the kb/mouse event to the application and before drawing.
- Unattended, and specifically with animations, the draw frequency was
throttled to `actionfps`. Animation at a higher rate would throttle
and likely tear, and at lower rates it was tearing big frames
(specifically, when one `read` didn't get a full "frame").
The interactive behavior was decent, but it was impossible to get good
unattended-draw behavior even with carefully chosen configuration.
This commit changes the behavior such that it draws on idle instead of
using fixed latency/frequency. This means that it tries to draw only
when it's very likely that the application has completed its output
(or after some duration without idle), so it mostly succeeds to avoid
tear, flicker, and partial drawing.
The config values minlatency/maxlatency replace xfps/actionfps and
define the range which the algorithm is allowed to wait from the
initial draw-trigger until the actual draw. The range enables the
flexibility to choose when to draw - when least likely to flicker.
It also unifies the interactive and unattended behavior and config
values, which makes the code simpler as well - without sacrificing
latency during interactive use, because typically interactively idle
arrives very quickly, so the wait is typically minlatency.
While it only slighly improves interactive behavior, for animations
and other unattended-drawing it improves greatly, as it effectively
adapts to any [animation] output rate without tearing, throttling,
redundant drawing, or unnecessary delays (sounds impossible, but it
works).
This line didn't work at mshortcuts at config.h:
/* mask button function arg release */
{ ShiftMask, Button2, selpaste, {.i = 0}, 1 },
and now it does work.
The issue was that XButtonEvent.state is "the logical state ... just prior
to the event", which means that on release the state has the Button2Mask
bit set because button2 was down just before it was released.
The issue didn't manifest with the default shift + middle-click on release
(to override mouse mode) because its specified modifier is XK_ANY_MOD, at
which case match(...) ignores any specific bits and simply returns true.
The issue also doesn't manifest on press, because prior to the event
Button<N> was not down and its mask bit is not set.
Fix by filtering out the mask of the button which we're currently matching.
We could have said "well, that's how button events behave, you should
use ShiftMask|Button2Mask for release", but this both not obvious to
figure out, and specifically here always filtering does not prevent
configuring any useful modifiers combination. So it's a win-win.
XCreateIC ICValues default XNFocusWindow to XNClientWindow if not
specified, it can be omitted since it is the same.
From the documentation
https://www.x.org/releases/current/doc/libX11/libX11/libX11.html
> Focus Window
>
> The XNFocusWindow argument specifies the focus window. The primary
> purpose of the XNFocusWindow is to identify the window that will receive
> the key event when input is composed.
>
> When this XIC value is left unspecified, the input method will use the
> client window as the default focus window.
Do not try to set specific IM method, let the user specify it with
XMODIFIERS.
If the requested method is not available or opening fails, fallback to
the default input handler and register a handler on the new IM server
availability signal.
Do the same when the input server is closed and (re)started.
Current buffer is too short to input medium to long sentences from IME.
Input with longer text will show the wrong input, taking 64 instead of
32 bytes should be enough for most of the cases. Broken cases before,
Chinese (taken from song 也可以)
可不可以轻轻的松开自己
Japanese (taken from bootleggers rom quote)
あなたは家のように感じる
For WM_CLASS this is mentioned in the ICCCM docs
https://tronche.com/gui/x/icccm/sec-4.html#s-4.1.2.5
(third sentence).
When changing the WM_CLASS from the command line, this is necessary for
window managers to pick it up before applying class-based rules.
The recent mouse shurtcuts commits allow customization, but ignore
forcemousemod mask (default: shift) as a modifier, for no good reason
other than following the behavior of the KB shortcuts.
Allow using forcemousemod too, which now can be used to invoke
different shortcuts, though the automatic effect of forcemousemod will
be lost for buttons which use mask with forcemousemod.
E.g. the default is:
static uint forcemousemod = ShiftMask;
...
{ XK_ANY_MOD, Button4, ttysend, {.s = "\031"} },
...
where ttysend will be invoked for button4 with any mod when not in mouse
mode, and with shift when in mouse mode.
Now it's possible to do this:
{ ShiftMask, Button4, ttysend, {.s = "foo"} },
{ XK_ANY_MOD, Button4, ttysend, {.s = "\031"} },
Which will invoke ttysend("foo") while shift is held and ttysend("\031")
otherwise. Shift still overrides mouse mode, but will now send "foo".
Previously with this setup the second binding was always invoked
because the forceousemod mask was always removed from the event.
Buttons which don't use forcemousemod behave the same as before.
This is useful e.g. for the scrollback mouse patch, which wants to
configure shift+wheel for scrollback, while keeping the normal behavior
without shift.
Because selpaste is activated on release, a release flag was added to
mouse shortcuts which controls whether activation is on press/release,
and selpaste binding to button2 was moved to config.h .
button1 remains the only hardcoded mouse button - for selection + copy.
Allow forceselmod to override all mouse shortcuts rather than only
selection, and rename it to forcemousemod as it's now more appropriate.
This will affect mouse shortcuts which use mask other than XK_ANY_MOD.
This does not affect the default behavior because the default mouse
shortcuts (wheel) use XK_ANY_MOD, where forceselmod already activated
the override also before this change.
Previously, if a mouse shortcut was configured with a specific mod and
forceselmod was held, then the shortcut did not execute unless the
configured mod included forceselmod.
Current font caching algorithm contains a use after free error. A font
removed from `frc` might be still listed in `wx.specbuf`. It will lead
to a crash inside `XftDrawGlyphFontSpec()`.
Steps to reproduce:
$ st -f 'Misc Tamsyn:scalable=false'
$ curl https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-demo.txt
Of course, result depends on fonts installed on a system and fontconfig.
In my case, I'm getting consistent segfaults with different fonts.
I replaced a fixed array with a simple unbounded buffer with a constant
growth rate. Cache starts with a capacity of 0, gets increments by 16,
and never shrinks. On my machine after `cat UTF-8-demo.txt` buffer
reaches a capacity of 192. During casual use capacity stays at 0.
Features:
- Allow input methods swap with hotkey (E.g. left ctrl + left shift).
- Over-the-spot pre-editing style, pre-edit data placed over insertion point.
- Restart IME without segmentation fault.
TODO:
- Automatically pickup IME if st started before IME
When possible, declare functions/variables static and move struct
definitions out of headers. In order to allow utf8decode to become
internal, use codepoint for DECSCUSR extension directly.
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
Prefer passing arguments to declaring external global variables. The
only remaining usage of extern is for config.h variables which are
needed in st.c instead of x.c (where it is now included).
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
The xinit function only needs to the rows/cols, so pass those in rather
than accessing term directly. With a bit of arithmetic, we are able to
avoid the need for term.row and term.col in x2col, y2row, and
xdrawglyphfontspecs as well, completing the removal.
Term is now fully internal to st.c.
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
Gradually reducing x.c dependency on Term object. Old and new cursor
glyph/position are passed to xdrawcursor. (There may be an opportunity
to refactor further if we can unify "clear old cursor" and "draw new
cursor" functionality.)
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
Introduces three functions to encapsulate X-specific behavior:
* xdrawline: draws a portion of a single line (used by drawregion)
* xbegindraw: called to prepare for drawing (will be useful for e.g.
Wayland) and returns true if drawing should happen
* xfinishdraw: called to finish drawing (used by draw)
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
Moves the mode bits used by x.c from Term to TermWindow, absorbing
UI/input-related mode bits (visible/focused/numlock) along the way.
This is gradually reducing external references to Term. Since
TermWindow is already internal to x.c, we add xsetmode() to allow st to
modify window bits in accordance with escape sequences.
IS_SET() is redefined accordingly (term.mode in st.c, win.mode in x.c).
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
This also allows us to remove the crlf field from the Key struct, since
the only difference it made was converting "\r" to "\r\n" (which is now
done automatically in ttywrite). In addition, MODE_CRLF is no longer
referenced from x.c.
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
The only thing differentiating ttywrite and ttysend was the potential
for echo; make this a parameter and remove ttysend.
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
The "done" parameter indicates a change which finalizes the selection
(e.g. a mouse button release as opposed to motion).
Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
