_frontend: Simplify color handling

Currently we store color configuration in our App object, and have to
remember to pass it around to `click.echo()` when printing things on the
screen. This is error-prone as we can forget to do so. This leads to
bugs like #1200, where `bst init` was not respecting `--no-colors` flag.

Instead of doing that, this patch controls colors in output by
configuring the `click.Context` object.

Fixes #1200.

3 files changed, 12 insertions, 13 deletions

diff --git a/src/buildstream/_frontend/app.py b/src/buildstream/_frontend/app.py
index 596ef168a..99e164358 100644
--- a/src/buildstream/_frontend/app.py
+++ b/src/buildstream/_frontend/app.py
@@ -251,7 +251,7 @@ class App():
             self._status = Status(self.context, self._state,
                                   self._content_profile, self._format_profile,
                                   self._success_profile, self._error_profile,
-                                  self.stream, colors=self.colors)
+                                  self.stream)
 
             # Mark the beginning of the session
             if session_name:
@@ -680,8 +680,7 @@ class App():
         if self._session_name:
             self.logger.print_heading(self.project,
                                       self.stream,
-                                      log_file=self._main_options['log_file'],
-                                      styling=self.colors)
+                                      log_file=self._main_options['log_file'])
 
     #
     # Print a summary of the queues
@@ -689,8 +688,7 @@ class App():
     def _print_summary(self):
         click.echo("", err=True)
         self.logger.print_summary(self.stream,
-                                  self._main_options['log_file'],
-                                  styling=self.colors)
+                                  self._main_options['log_file'])
 
     # _error_exit()
     #
@@ -749,7 +747,7 @@ class App():
             self._status.clear()
 
         text = self.logger.render(message)
-        click.echo(text, color=self.colors, nl=False, err=True)
+        click.echo(text, nl=False, err=True)
 
         # Maybe render the status area
         self._maybe_render_status()
diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py
index 67ea02d59..5c0293589 100644
--- a/src/buildstream/_frontend/cli.py
+++ b/src/buildstream/_frontend/cli.py
@@ -353,6 +353,9 @@ def cli(context, **kwargs):
     context.obj = App.create(dict(kwargs))
     context.call_on_close(context.obj.cleanup)
 
+    # Configure colors
+    context.color = context.obj.colors
+
 
 ##################################################################
 #                           Help Command                         #
@@ -544,7 +547,7 @@ def show(app, elements, deps, except_, order, format_):
             format_ = app.context.log_element_format
 
         report = app.logger.show_pipeline(dependencies, format_)
-        click.echo(report, color=app.colors)
+        click.echo(report)
 
 
 ##################################################################
diff --git a/src/buildstream/_frontend/widget.py b/src/buildstream/_frontend/widget.py
index 181ee7d2e..0a268b717 100644
--- a/src/buildstream/_frontend/widget.py
+++ b/src/buildstream/_frontend/widget.py
@@ -459,9 +459,8 @@ class LogLine(Widget):
     #    project (Project): The toplevel project we were invoked from
     #    stream (Stream): The stream
     #    log_file (file): An optional file handle for additional logging
-    #    styling (bool): Whether to enable ansi escape codes in the output
     #
-    def print_heading(self, project, stream, *, log_file, styling=False):
+    def print_heading(self, project, stream, *, log_file):
         context = self.context
         starttime = datetime.datetime.now()
         text = ''
@@ -518,7 +517,7 @@ class LogLine(Widget):
         # Separator line before following output
         text += self.format_profile.fmt("=" * 79 + '\n')
 
-        click.echo(text, color=styling, nl=False, err=True)
+        click.echo(text, nl=False, err=True)
         if log_file:
             click.echo(text, file=log_file, color=False, nl=False)
 
@@ -529,9 +528,8 @@ class LogLine(Widget):
     # Args:
     #    stream (Stream): The Stream
     #    log_file (file): An optional file handle for additional logging
-    #    styling (bool): Whether to enable ansi escape codes in the output
     #
-    def print_summary(self, stream, log_file, styling=False):
+    def print_summary(self, stream, log_file):
 
         # Early silent return if there are no queues, can happen
         # only in the case that the stream early returned due to
@@ -599,7 +597,7 @@ class LogLine(Widget):
 
         text += self._format_values(values, style_value=False)
 
-        click.echo(text, color=styling, nl=False, err=True)
+        click.echo(text, nl=False, err=True)
         if log_file:
             click.echo(text, file=log_file, color=False, nl=False)