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Diffstat (limited to 'vendor/github.com/gdamore/tcell/screen.go')
| -rw-r--r-- | vendor/github.com/gdamore/tcell/screen.go | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/vendor/github.com/gdamore/tcell/screen.go b/vendor/github.com/gdamore/tcell/screen.go new file mode 100644 index 0000000..9551af6 --- /dev/null +++ b/vendor/github.com/gdamore/tcell/screen.go @@ -0,0 +1,212 @@ +// Copyright 2016 The TCell Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use file except in compliance with the License. +// You may obtain a copy of the license at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package tcell + +// Screen represents the physical (or emulated) screen. +// This can be a terminal window or a physical console. Platforms implement +// this differerently. +type Screen interface { + // Init initializes the screen for use. + Init() error + + // Fini finalizes the screen also releasing resources. + Fini() + + // Clear erases the screen. The contents of any screen buffers + // will also be cleared. This has the logical effect of + // filling the screen with spaces, using the global default style. + Clear() + + // Fill fills the screen with the given character and style. + Fill(rune, Style) + + // SetCell is an older API, and will be removed. Please use + // SetContent instead; SetCell is implemented in terms of SetContent. + SetCell(x int, y int, style Style, ch ...rune) + + // GetContent returns the contents at the given location. If the + // coordinates are out of range, then the values will be 0, nil, + // StyleDefault. Note that the contents returned are logical contents + // and may not actually be what is displayed, but rather are what will + // be displayed if Show() or Sync() is called. The width is the width + // in screen cells; most often this will be 1, but some East Asian + // characters require two cells. + GetContent(x, y int) (mainc rune, combc []rune, style Style, width int) + + // SetContent sets the contents of the given cell location. If + // the coordinates are out of range, then the operation is ignored. + // + // The first rune is the primary non-zero width rune. The array + // that follows is a possible list of combining characters to append, + // and will usually be nil (no combining characters.) + // + // The results are not displayd until Show() or Sync() is called. + // + // Note that wide (East Asian full width) runes occupy two cells, + // and attempts to place character at next cell to the right will have + // undefined effects. Wide runes that are printed in the + // last column will be replaced with a single width space on output. + SetContent(x int, y int, mainc rune, combc []rune, style Style) + + // SetStyle sets the default style to use when clearing the screen + // or when StyleDefault is specified. If it is also StyleDefault, + // then whatever system/terminal default is relevant will be used. + SetStyle(style Style) + + // ShowCursor is used to display the cursor at a given location. + // If the coordinates -1, -1 are given or are otherwise outside the + // dimensions of the screen, the cursor will be hidden. + ShowCursor(x int, y int) + + // HideCursor is used to hide the cursor. Its an alias for + // ShowCursor(-1, -1). + HideCursor() + + // Size returns the screen size as width, height. This changes in + // response to a call to Clear or Flush. + Size() (int, int) + + // PollEvent waits for events to arrive. Main application loops + // must spin on this to prevent the application from stalling. + // Furthermore, this will return nil if the Screen is finalized. + PollEvent() Event + + // PostEvent tries to post an event into the event stream. This + // can fail if the event queue is full. In that case, the event + // is dropped, and ErrEventQFull is returned. + PostEvent(ev Event) error + + // PostEventWait is like PostEvent, but if the queue is full, it + // blocks until there is space in the queue, making delivery + // reliable. However, it is VERY important that this function + // never be called from within whatever event loop is polling + // with PollEvent(), otherwise a deadlock may arise. + // + // For this reason, when using this function, the use of a + // Goroutine is recommended to ensure no deadlock can occur. + PostEventWait(ev Event) + + // EnableMouse enables the mouse. (If your terminal supports it.) + EnableMouse() + + // DisableMouse disables the mouse. + DisableMouse() + + // HasMouse returns true if the terminal (apparently) supports a + // mouse. Note that the a return value of true doesn't guarantee that + // a mouse/pointing device is present; a false return definitely + // indicates no mouse support is available. + HasMouse() bool + + // Colors returns the number of colors. All colors are assumed to + // use the ANSI color map. If a terminal is monochrome, it will + // return 0. + Colors() int + + // Show makes all the content changes made using SetContent() visible + // on the display. + // + // It does so in the most efficient and least visually disruptive + // manner possible. + Show() + + // Sync works like Show(), but it updates every visible cell on the + // physical display, assuming that it is not synchronized with any + // internal model. This may be both expensive and visually jarring, + // so it should only be used when believed to actually be necessary. + // + // Typically this is called as a result of a user-requested redraw + // (e.g. to clear up on screen corruption caused by some other program), + // or during a resize event. + Sync() + + // CharacterSet returns information about the character set. + // This isn't the full locale, but it does give us the input/output + // character set. Note that this is just for diagnostic purposes, + // we normally translate input/output to/from UTF-8, regardless of + // what the user's environment is. + CharacterSet() string + + // RegisterRuneFallback adds a fallback for runes that are not + // part of the character set -- for example one coudld register + // o as a fallback for ΓΈ. This should be done cautiously for + // characters that might be displayed ordinarily in language + // specific text -- characters that could change the meaning of + // of written text would be dangerous. The intention here is to + // facilitate fallback characters in pseudo-graphical applications. + // + // If the terminal has fallbacks already in place via an alternate + // character set, those are used in preference. Also, standard + // fallbacks for graphical characters in the ACSC terminfo string + // are registered implicitly. + + // The display string should be the same width as original rune. + // This makes it possible to register two character replacements + // for full width East Asian characters, for example. + // + // It is recommended that replacement strings consist only of + // 7-bit ASCII, since other characters may not display everywhere. + RegisterRuneFallback(r rune, subst string) + + // UnregisterRuneFallback unmaps a replacement. It will unmap + // the implicit ASCII replacements for alternate characters as well. + // When an unmapped char needs to be displayed, but no suitable + // glyph is available, '?' is emitted instead. It is not possible + // to "disable" the use of alternate characters that are supported + // by your terminal except by changing the terminal database. + UnregisterRuneFallback(r rune) + + // CanDisplay returns true if the given rune can be displayed on + // this screen. Note that this is a best guess effort -- whether + // your fonts support the character or not may be questionable. + // Mostly this is for folks who work outside of Unicode. + // + // If checkFallbacks is true, then if any (possibly imperfect) + // fallbacks are registered, this will return true. This will + // also return true if the terminal can replace the glyph with + // one that is visually indistinguishable from the one requested. + CanDisplay(r rune, checkFallbacks bool) bool + + // Resize does nothing, since its generally not possible to + // ask a screen to resize, but it allows the Screen to implement + // the View interface. + Resize(int, int, int, int) + + // HasKey returns true if the keyboard is believed to have the + // key. In some cases a keyboard may have keys with this name + // but no support for them, while in others a key may be reported + // as supported but not actually be usable (such as some emulators + // that hijack certain keys). Its best not to depend to strictly + // on this function, but it can be used for hinting when building + // menus, displayed hot-keys, etc. Note that KeyRune (literal + // runes) is always true. + HasKey(Key) bool +} + +// NewScreen returns a default Screen suitable for the user's terminal +// environment. +func NewScreen() (Screen, error) { + // First we attempt to obtain a terminfo screen. This should work + // in most places if $TERM is set. + if s, e := NewTerminfoScreen(); s != nil { + return s, nil + + } else if s, _ := NewConsoleScreen(); s != nil { + return s, nil + + } else { + return nil, e + } +} |