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Building a Callout Control

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August, 2004: Building a Callout Control

Message Wrapper macro Description
WM_GETFONT Font handle to use for the text
WM_GETICON Icon handle (optional)
CM_GETANCHOR Callout_GetAnchor(hwnd) Position of anchor in client coordinates
CM_SETANCHOR Callout_SetAnchor(hwnd, x, y)
CM_GETBACKCOLOR Callout_GetBackColor(hwnd) Color of interior of balloon
CM_SETBACKCOLOR Callout_SetBackColor(hwnd, Color, Repaint)
CM_GETBORDER Callout_GetBorder(hwnd) Border thickness
CM_SETBORDER Callout_SetBorder(hwnd, Width, Repaint)
CM_GETDRAWTEXTPROC Callout_GetDrawTextProc(hwnd) Text drawing function to replace DrawText()
CM_SETDRAWTEXTPROC Callout_SetDrawTextProc(hwnd, Proc, Repaint)
CM_GETEXTRAHEIGHT Callout_GetExtraHeight(hwnd) Extra height of balloon text box
CM_SETEXTRAHEIGHT Callout_SetExtraHeight(hwnd, Height, Repaint)
CM_GETMINWIDTH Callout_GetMinWidth(hwnd) Minimum width of balloon text box
CM_SETMINWIDTH Callout_SetMinWidth(hwnd, Width, Repaint)
CM_GETRADIUS Callout_GetRadius(hwnd) Radius of rectangle rounding
CM_SETRADIUS Callout_SetRadius(hwnd, Radius, Repaint)
CM_GETRECT Callout_GetRect(hwnd) Position and size of balloon text box
CM_GETTAILHEIGHT Callout_GetTailHeight(hwnd) Height of tail in pixels
CM_SETTAILHEIGHT Callout_SetTailHeight(hwnd, Height, Repaint)
CM_GETTAILJOIN Callout_GetTailJoin(hwnd) Horizontal position where tail joins balloon; a percentage of the balloon width
CM_SETTAILJOIN Callout_SetTailJoin(hwnd, Join, Repaint)
CM_GETTAILOFFSET Callout_GetTailOffset(hwnd) Vertical offset of tail to anchor point
CM_SETTAILOFFSET Callout_SetTailOffset(hwnd, Offset, Repaint)
CM_GETTAILSLANT Callout_GetTailSlant(hwnd) Tail slant (tangent of the angle); a negative value slants to the left
CM_SETTAILSLANT Callout_SetTailSlant(hwnd, Slant, Repaint)
CM_GETTAILSTYLE Callout_GetTailStyle(hwnd) Tail style: CS_SPEAK or CS_THINK
CM_SETTAILSTYLE Callout_SetTailStyle(hwnd, Style, Repaint)
CM_GETTAILWIDTH Callout_GetTailWidth(hwnd) Width of the tail where it joins the balloon
CM_SETTAILWIDTH Callout_SetTailWidth(hwnd, Width, Repaint)
CM_GETTEXTCOLOR Callout_GetTextColor(hwnd) Color of the text and border of the callout
CM_SETTEXTCOLOR Callout_SetTextColor(hwnd, Color, Repaint)
CM_GETTIMEOUT Callout_GetTimeout(hwnd) Timeout in milliseconds; 0 = no timeout
CM_SETTIMEOUT Callout_SetTimeout(hwnd, Timeout)
CM_GETVERTALIGN Callout_GetVertAlign(hwnd) Alignment of callout relative to the anchor point: CS_ALIGNABOVE or CS_ALIGNBELOW
CM_SETVERTALIGN Callout_SetVertAlign(hwnd, Alignment, Repaint)

Table 1: An overview of the standard and custom messages that you can send to the callout control.

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