diff options
Diffstat (limited to 'vendor/github.com/Azure/go-ansiterm/winterm/scroll_helper.go')
-rw-r--r-- | vendor/github.com/Azure/go-ansiterm/winterm/scroll_helper.go | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/vendor/github.com/Azure/go-ansiterm/winterm/scroll_helper.go b/vendor/github.com/Azure/go-ansiterm/winterm/scroll_helper.go new file mode 100644 index 000000000..706d27057 --- /dev/null +++ b/vendor/github.com/Azure/go-ansiterm/winterm/scroll_helper.go @@ -0,0 +1,118 @@ +// +build windows + +package winterm + +// effectiveSr gets the current effective scroll region in buffer coordinates +func (h *windowsAnsiEventHandler) effectiveSr(window SMALL_RECT) scrollRegion { + top := addInRange(window.Top, h.sr.top, window.Top, window.Bottom) + bottom := addInRange(window.Top, h.sr.bottom, window.Top, window.Bottom) + if top >= bottom { + top = window.Top + bottom = window.Bottom + } + return scrollRegion{top: top, bottom: bottom} +} + +func (h *windowsAnsiEventHandler) scrollUp(param int) error { + info, err := GetConsoleScreenBufferInfo(h.fd) + if err != nil { + return err + } + + sr := h.effectiveSr(info.Window) + return h.scroll(param, sr, info) +} + +func (h *windowsAnsiEventHandler) scrollDown(param int) error { + return h.scrollUp(-param) +} + +func (h *windowsAnsiEventHandler) deleteLines(param int) error { + info, err := GetConsoleScreenBufferInfo(h.fd) + if err != nil { + return err + } + + start := info.CursorPosition.Y + sr := h.effectiveSr(info.Window) + // Lines cannot be inserted or deleted outside the scrolling region. + if start >= sr.top && start <= sr.bottom { + sr.top = start + return h.scroll(param, sr, info) + } else { + return nil + } +} + +func (h *windowsAnsiEventHandler) insertLines(param int) error { + return h.deleteLines(-param) +} + +// scroll scrolls the provided scroll region by param lines. The scroll region is in buffer coordinates. +func (h *windowsAnsiEventHandler) scroll(param int, sr scrollRegion, info *CONSOLE_SCREEN_BUFFER_INFO) error { + logger.Infof("scroll: scrollTop: %d, scrollBottom: %d", sr.top, sr.bottom) + logger.Infof("scroll: windowTop: %d, windowBottom: %d", info.Window.Top, info.Window.Bottom) + + // Copy from and clip to the scroll region (full buffer width) + scrollRect := SMALL_RECT{ + Top: sr.top, + Bottom: sr.bottom, + Left: 0, + Right: info.Size.X - 1, + } + + // Origin to which area should be copied + destOrigin := COORD{ + X: 0, + Y: sr.top - int16(param), + } + + char := CHAR_INFO{ + UnicodeChar: ' ', + Attributes: h.attributes, + } + + if err := ScrollConsoleScreenBuffer(h.fd, scrollRect, scrollRect, destOrigin, char); err != nil { + return err + } + return nil +} + +func (h *windowsAnsiEventHandler) deleteCharacters(param int) error { + info, err := GetConsoleScreenBufferInfo(h.fd) + if err != nil { + return err + } + return h.scrollLine(param, info.CursorPosition, info) +} + +func (h *windowsAnsiEventHandler) insertCharacters(param int) error { + return h.deleteCharacters(-param) +} + +// scrollLine scrolls a line horizontally starting at the provided position by a number of columns. +func (h *windowsAnsiEventHandler) scrollLine(columns int, position COORD, info *CONSOLE_SCREEN_BUFFER_INFO) error { + // Copy from and clip to the scroll region (full buffer width) + scrollRect := SMALL_RECT{ + Top: position.Y, + Bottom: position.Y, + Left: position.X, + Right: info.Size.X - 1, + } + + // Origin to which area should be copied + destOrigin := COORD{ + X: position.X - int16(columns), + Y: position.Y, + } + + char := CHAR_INFO{ + UnicodeChar: ' ', + Attributes: h.attributes, + } + + if err := ScrollConsoleScreenBuffer(h.fd, scrollRect, scrollRect, destOrigin, char); err != nil { + return err + } + return nil +} |