Rework how the devshell functions

In the new implementation, each known terminal is defined as a class in
oe.terminal, as a subclass of bb.process.Popen.  terminal.bbclass wraps this
functionality, providing the metadata pieces.  It obeys the OE_TERMINAL
variable, which is a 'choice' typed variable.  This variable may be 'auto',
'none', or any of the names of the defined terminals.

When using 'auto', or requesting an unsupported terminal, we attempt to spawn
them in priority order until we get one that's available on this system (and
in the case of the X terminals, has DISPLAY defined).  The 'none' value is
used when we're doing things like automated builds, and want to ensure that no
terminal is *ever* spawned, under any circumstances.

Current available terminals:

    gnome
    konsole
    xterm
    rxvt
    screen

Signed-off-by: Chris Larson <chris_larson@mentor.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/meta/classes/terminal.bbclass b/meta/classes/terminal.bbclass
new file mode 100644
index 000000000..41230466c
--- /dev/null
+++ b/meta/classes/terminal.bbclass
@@ -0,0 +1,40 @@
+OE_TERMINAL ?= 'auto'
+OE_TERMINAL[type] = 'choice'
+OE_TERMINAL[choices] = 'auto none \
+                        ${@" ".join(o.name \
+                                    for o in oe.terminal.prioritized())}'
+
+OE_TERMINAL_EXPORTS = 'XAUTHORITY SHELL DBUS_SESSION_BUS_ADDRESS DISPLAY EXTRA_OEMAKE'
+OE_TERMINAL_EXPORTS[type] = 'list'
+
+XAUTHORITY ?= "${HOME}/.Xauthority"
+SHELL ?= "bash"
+
+
+def oe_terminal(command, title, d):
+    import oe.data
+    import oe.terminal
+
+    terminal = oe.data.typed_value('OE_TERMINAL', d).lower()
+    if terminal == 'none':
+        bb.fatal('Devshell usage disabled with OE_TERMINAL')
+    elif terminal != 'auto':
+        try:
+            oe.terminal.spawn(terminal, command, title)
+            return
+        except oe.terminal.UnsupportedTerminal:
+            bb.warn('Unsupported terminal "%s", defaulting to "auto"' %
+                    terminal)
+        except oe.terminal.ExecutionError as exc:
+            bb.fatal('Unable to spawn terminal %s: %s' % (terminal, exc))
+
+    env = dict(os.environ)
+    for export in oe.data.typed_value('OE_TERMINAL_EXPORTS', d):
+        env[export] = d.getVar(export, True)
+
+    try:
+        oe.terminal.spawn_preferred(command, title, env)
+    except oe.terminal.NoSupportedTerminals:
+        bb.fatal('No valid terminal found, unable to open devshell')
+    except oe.terminal.ExecutionError as exc:
+        bb.fatal('Unable to spawn terminal %s: %s' % (terminal, exc))