{Style} Refine style framework

src/azure-cli-core/azure/cli/core/__init__.py

@@ -49,6 +49,7 @@ def __init__(self, **kwargs):
         from azure.cli.core.cloud import get_active_cloud
         from azure.cli.core.commands.transform import register_global_transforms
         from azure.cli.core._session import ACCOUNT, CONFIG, SESSION, INDEX, VERSIONS
+        from azure.cli.core.style import format_styled_text
         from azure.cli.core.util import handle_version_update
         from azure.cli.core.commands.query_examples import register_global_query_examples_argument
 
@@ -80,6 +81,9 @@ def __init__(self, **kwargs):
 
         self.progress_controller = None
 
+        if not self.enable_color:
+            format_styled_text.theme = 'none'
+
         _configure_knack()
 
     def refresh_request_id(self):
@@ -104,17 +108,18 @@ def get_cli_version(self):
 
     def show_version(self):
         from azure.cli.core.util import get_az_version_string, show_updates
-        from azure.cli.core.commands.constants import (SURVEY_PROMPT, SURVEY_PROMPT_COLOR,
-                                                       UX_SURVEY_PROMPT, UX_SURVEY_PROMPT_COLOR)
+        from azure.cli.core.commands.constants import SURVEY_PROMPT_STYLED, UX_SURVEY_PROMPT_STYLED
+        from azure.cli.core.style import print_styled_text
 
         ver_string, updates_available_components = get_az_version_string()
         print(ver_string)
         show_updates(updates_available_components)
 
         show_link = self.config.getboolean('output', 'show_survey_link', True)
         if show_link:
-            print('\n' + (SURVEY_PROMPT_COLOR if self.enable_color else SURVEY_PROMPT))
-            print(UX_SURVEY_PROMPT_COLOR if self.enable_color else UX_SURVEY_PROMPT)
+            print_styled_text()
+            print_styled_text(SURVEY_PROMPT_STYLED)
+            print_styled_text(UX_SURVEY_PROMPT_STYLED)
 
     def exception_handler(self, ex):  # pylint: disable=no-self-use
         from azure.cli.core.util import handle_exception

src/azure-cli-core/azure/cli/core/_help.py

@@ -7,8 +7,6 @@
 import argparse
 
 from azure.cli.core.commands import ExtensionCommandSource
-from azure.cli.core.commands.constants import (SURVEY_PROMPT, SURVEY_PROMPT_COLOR,
-                                               UX_SURVEY_PROMPT, UX_SURVEY_PROMPT_COLOR)
 
 from knack.help import (HelpFile as KnackHelpFile, CommandHelpFile as KnackCommandHelpFile,
                         GroupHelpFile as KnackGroupHelpFile, ArgumentGroupRegistry as KnackArgumentGroupRegistry,
@@ -178,10 +176,12 @@ def show_help(self, cli_name, nouns, parser, is_group):
         from azure.cli.core.util import show_updates_available
         show_updates_available(new_line_after=True)
         show_link = self.cli_ctx.config.getboolean('output', 'show_survey_link', True)
+        from azure.cli.core.commands.constants import (SURVEY_PROMPT_STYLED, UX_SURVEY_PROMPT_STYLED)
+        from azure.cli.core.style import print_styled_text
         if show_link:
-            print(SURVEY_PROMPT_COLOR if self.cli_ctx.enable_color else SURVEY_PROMPT)
+            print_styled_text(SURVEY_PROMPT_STYLED)
             if not nouns:
-                print(UX_SURVEY_PROMPT_COLOR if self.cli_ctx.enable_color else UX_SURVEY_PROMPT)
+                print_styled_text(UX_SURVEY_PROMPT_STYLED)
 
     def get_examples(self, command, parser, is_group):
         """Get examples of a certain command from the help file.

src/azure-cli-core/azure/cli/core/commands/constants.py

@@ -3,7 +3,7 @@
 # Licensed under the MIT License. See License.txt in the project root for license information.
 # --------------------------------------------------------------------------------------------
 
-from colorama import Fore, Style
+from azure.cli.core.style import Style
 from knack.parser import ARGPARSE_SUPPORTED_KWARGS
 
 
@@ -33,9 +33,13 @@
 BLOCKED_MODS = ['context', 'shell', 'documentdb', 'component']
 
 SURVEY_PROMPT = 'Please let us know how we are doing: https://aka.ms/azureclihats'
-SURVEY_PROMPT_COLOR = Fore.YELLOW + Style.BRIGHT + 'Please let us know how we are doing: ' + Fore.BLUE + \
-    'https://aka.ms/azureclihats' + Style.RESET_ALL
+SURVEY_PROMPT_STYLED = [
+    (Style.PRIMARY, 'Please let us know how we are doing: '),
+    (Style.HYPERLINK, 'https://aka.ms/azureclihats'),
+]
+
 UX_SURVEY_PROMPT = 'and let us know if you\'re interested in trying out our newest features: https://aka.ms/CLIUXstudy'
-UX_SURVEY_PROMPT_COLOR = Fore.YELLOW + Style.BRIGHT + \
-    'and let us know if you\'re interested in trying out our newest features: ' \
-    + Fore.BLUE + 'https://aka.ms/CLIUXstudy' + Style.RESET_ALL
+UX_SURVEY_PROMPT_STYLED = [
+    (Style.PRIMARY, 'and let us know if you\'re interested in trying out our newest features: '),
+    (Style.HYPERLINK, 'https://aka.ms/CLIUXstudy'),
+]

src/azure-cli-core/azure/cli/core/style.py

@@ -14,6 +14,7 @@
 For a complete demo, see `src/azure-cli/azure/cli/command_modules/util/custom.py` and run `az demo style`.
 """
 
+import os
 import sys
 from enum import Enum
 
@@ -32,10 +33,14 @@ class Style(str, Enum):
     WARNING = "warning"
 
 
-THEME = {
+# Theme that doesn't contain any style
+THEME_NONE = {}
+
+# Theme to be used on a dark-themed terminal
+THEME_DARK = {
     # Style to ANSI escape sequence mapping
     # https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
-    Style.PRIMARY: Fore.LIGHTWHITE_EX,
+    Style.PRIMARY: Fore.RESET,
     Style.SECONDARY: Fore.LIGHTBLACK_EX,  # may use WHITE, but will lose contrast to LIGHTWHITE_EX
     Style.IMPORTANT: Fore.LIGHTMAGENTA_EX,
     Style.ACTION: Fore.LIGHTBLUE_EX,
@@ -46,29 +51,138 @@ class Style(str, Enum):
     Style.WARNING: Fore.LIGHTYELLOW_EX,
 }
 
+# Theme to be used on a light-themed terminal
+THEME_LIGHT = {
+    Style.PRIMARY: Fore.RESET,
+    Style.SECONDARY: Fore.LIGHTBLACK_EX,
+    Style.IMPORTANT: Fore.MAGENTA,
+    Style.ACTION: Fore.BLUE,
+    Style.HYPERLINK: Fore.CYAN,
+    Style.ERROR: Fore.RED,
+    Style.SUCCESS: Fore.GREEN,
+    Style.WARNING: Fore.YELLOW,
+}
+
+
+class Theme(str, Enum):
+    DARK = 'dark'
+    LIGHT = 'light'
+    NONE = 'none'
+
+
+THEME_DEFINITIONS = {
+    Theme.NONE: THEME_NONE,
+    Theme.DARK: THEME_DARK,
+    Theme.LIGHT: THEME_LIGHT
+}
+
+# Blue and bright blue is not visible under the default theme of powershell.exe
+POWERSHELL_COLOR_REPLACEMENT = {
+    Fore.BLUE: Fore.RESET,
+    Fore.LIGHTBLUE_EX: Fore.RESET
+}
+
+
+def print_styled_text(*styled_text_objects, file=None, **kwargs):
+    """
+    Print styled text. This function wraps the built-in function `print`, additional arguments can be sent
+    via keyword arguments.
+
+    :param styled_text_objects: The input text objects. See format_styled_text for formats of each object.
+    :param file: The file to print the styled text. The default target is sys.stderr.
+    """
+    formatted_list = [format_styled_text(obj) for obj in styled_text_objects]
+    # Always fetch the latest sys.stderr in case it has been wrapped by colorama.
+    print(*formatted_list, file=file or sys.stderr, **kwargs)
 
-def print_styled_text(styled, file=sys.stderr):
-    formatted = format_styled_text(styled)
-    print(formatted, file=file)
 
+def format_styled_text(styled_text, theme=None):
+    """Format styled text. Dark theme used by default. Available themes are 'dark', 'light', 'none'.
+
+    To change theme for all invocations of this function, set `format_styled_text.theme`.
+    To change theme for one invocation, set parameter `theme`.
+
+    :param styled_text: Can be in these formats:
+        - text
+        - (style, text)
+        - [(style, text), ...]
+    :param theme: The theme used to format text. Can be theme name str, `Theme` Enum or dict.
+    """
+    if theme is None:
+        theme = getattr(format_styled_text, "theme", THEME_DARK)
+
+    # Convert str to the theme dict
+    if isinstance(theme, str):
+        try:
+            theme = THEME_DEFINITIONS[theme]
+        except KeyError:
+            from azure.cli.core.azclierror import CLIInternalError
+            raise CLIInternalError("Invalid theme. Supported themes: none, dark, light")
+
+    # Cache the value of is_legacy_powershell
+    if not hasattr(format_styled_text, "_is_legacy_powershell"):
+        from azure.cli.core.util import get_parent_proc_name
+        is_legacy_powershell = not is_modern_terminal() and get_parent_proc_name() == "powershell.exe"
+        setattr(format_styled_text, "_is_legacy_powershell", is_legacy_powershell)
+    is_legacy_powershell = getattr(format_styled_text, "_is_legacy_powershell")
 
-def format_styled_text(styled_text):
     # https://python-prompt-toolkit.readthedocs.io/en/stable/pages/printing_text.html#style-text-tuples
     formatted_parts = []
 
+    # A str as PRIMARY text
+    if isinstance(styled_text, str):
+        styled_text = [(Style.PRIMARY, styled_text)]
+
+    # A tuple
+    if isinstance(styled_text, tuple):
+        styled_text = [styled_text]
+
     for text in styled_text:
         # str can also be indexed, bypassing IndexError, so explicitly check if the type is tuple
         if not (isinstance(text, tuple) and len(text) == 2):
             from azure.cli.core.azclierror import CLIInternalError
             raise CLIInternalError("Invalid styled text. It should be a list of 2-element tuples.")
 
-        style = text[0]
-        if style not in THEME:
-            from azure.cli.core.azclierror import CLIInternalError
-            raise CLIInternalError("Invalid style. Only use pre-defined style in Style enum.")
-
-        formatted_parts.append(THEME[text[0]] + text[1])
+        style, raw_text = text
+
+        if theme is THEME_NONE:
+            formatted_parts.append(raw_text)
+        else:
+            try:
+                escape_seq = theme[style]
+            except KeyError:
+                from azure.cli.core.azclierror import CLIInternalError
+                raise CLIInternalError("Invalid style. Only use pre-defined style in Style enum.")
+            # Replace blue in powershell.exe
+            if is_legacy_powershell and escape_seq in POWERSHELL_COLOR_REPLACEMENT:
+                escape_seq = POWERSHELL_COLOR_REPLACEMENT[escape_seq]
+            formatted_parts.append(escape_seq + raw_text)
 
     # Reset control sequence
-    formatted_parts.append(Fore.RESET)
+    if theme is not THEME_NONE:
+        formatted_parts.append(Fore.RESET)
     return ''.join(formatted_parts)
+
+
+def _is_modern_terminal():
+    # Windows Terminal: https://github.com/microsoft/terminal/issues/1040
+    if 'WT_SESSION' in os.environ:
+        return True
+    # VS Code: https://github.com/microsoft/vscode/pull/30346
+    if os.environ.get('TERM_PROGRAM', '').lower() == 'vscode':
+        return True
+    return False
+
+
+def is_modern_terminal():
+    """Detect whether the current terminal is a modern terminal that supports Unicode and
+    Console Virtual Terminal Sequences.
+
+    Currently, these terminals can be detected:
+      - Windows Terminal
+      - VS Code terminal
+    """
+    # This function wraps _is_modern_terminal and use a function-level cache to save the result.
+    if not hasattr(is_modern_terminal, "return_value"):
+        setattr(is_modern_terminal, "return_value", _is_modern_terminal())
+    return getattr(is_modern_terminal, "return_value")