[PATCH 22/22] Copy variable value to clipboard on middle-click

[Hannes Domani <ssbssa@yahoo.de>]

For variables that don't have children, or the children tree is closed, its
text representation is copied.
If the variable has children, and the children tree is opened, the text
representation of the children is copied instead (each on a separate line).

I could imagine customizable actions on middle-click on VariableWindow
variables, like some kind of callback function.

I chose the clipboard myself because I relatively often have classes for
graphical objects like lines and arcs.
For easier readability, I created simple pretty printers, like:

    LINE 0 0 100 0
    ARC 50 0 50 0 3.1415

So a middle-click on an opened vector containing these objects copies their
text representation to the clipboard.

I have another tool that is notified whenever the clipboard contents change,
and if they are in this specific format, immediately visualizes them.

The result is a relatively convenient way to visualize these graphical objects
from the debugger, with a single mouse-click.
---
 gdb/python/lib/gdb/command/tui_windows.py | 76 +++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/gdb/python/lib/gdb/command/tui_windows.py b/gdb/python/lib/gdb/command/tui_windows.py
index 45ba9502878..050ef4d1ddf 100644
--- a/gdb/python/lib/gdb/command/tui_windows.py
+++ b/gdb/python/lib/gdb/command/tui_windows.py
@@ -23,6 +23,62 @@ PY3 = sys.version_info[0] == 3
 custom_windows = {}
 
 
+if sys.platform == 'win32':
+    import ctypes
+    import ctypes.wintypes as w
+
+    CF_TEXT = 1
+
+    u32 = ctypes.WinDLL('user32')
+    k32 = ctypes.WinDLL('kernel32')
+
+    OpenClipboard = u32.OpenClipboard
+    OpenClipboard.argtypes = w.HWND,
+    OpenClipboard.restype = w.BOOL
+
+    EmptyClipboard = u32.EmptyClipboard
+    EmptyClipboard.restype = w.BOOL
+
+    SetClipboardData = u32.SetClipboardData
+    SetClipboardData.argtypes = w.UINT, w.HANDLE,
+    SetClipboardData.restype = w.HANDLE
+
+    CloseClipboard = u32.CloseClipboard
+    CloseClipboard.restype = w.BOOL
+
+    GHND = 0x0042
+
+    GlobalAlloc = k32.GlobalAlloc
+    GlobalAlloc.argtypes = w.UINT, ctypes.c_size_t,
+    GlobalAlloc.restype = w.HGLOBAL
+
+    GlobalLock = k32.GlobalLock
+    GlobalLock.argtypes = w.HGLOBAL,
+    GlobalLock.restype = w.LPVOID
+
+    GlobalUnlock = k32.GlobalUnlock
+    GlobalUnlock.argtypes = w.HGLOBAL,
+    GlobalUnlock.restype = w.BOOL
+
+    def set_clipboard_text(s):
+        if OpenClipboard(None):
+            s = s.encode('utf-8')
+            EmptyClipboard()
+            h = GlobalAlloc(GHND, len(s) + 1)
+            p = GlobalLock(h)
+            ctypes.memmove(p, s, len(s))
+            GlobalUnlock(h)
+            SetClipboardData(CF_TEXT, h)
+            CloseClipboard()
+
+else:
+    import base64
+
+    def set_clipboard_text(s):
+        b64 = base64.b64encode(s.encode('utf-8')).decode()
+        sys.__stdout__.write("\x1b]52;c;" + b64 + "\x07")
+
+
 col_esc_seq_re = re.compile('(\033\[[0-9;]*m)')
 def escaped_substr(s, n, c):
     col_esc_seq = False
@@ -189,6 +245,26 @@ class VariableWindow(TextWindow):
                 if prev is not None and prev[3] is not None:
                     gdb.set_convenience_variable(self.convenience_name, prev[3])
                     self.refill(True)
+        elif button == 2 and line < len(self.line_names):
+            name = self.line_names[line]
+            if name:
+                prev = self.prev_vals[name]
+                if prev is not None:
+                    if prev[0]:
+                        name2 = name + ":"
+                        child_texts = []
+                        for l in range(line + 1, len(self.line_names)):
+                            child_name = self.line_names[l]
+                            if not child_name:
+                                continue
+                            if not child_name.startswith(name2):
+                                break
+                            child = self.prev_vals[child_name]
+                            if child is not None and child[1] != False:
+                                child_texts.append(child[1])
+                        set_clipboard_text("\n".join(child_texts))
+                    elif prev[1] != False:
+                        set_clipboard_text(prev[1])
 
     def refill(self, keep_prev=False):
         if not self.win.is_valid():
-- 
2.30.1