textarea.go

Documentation: github.com/gdamore/tcell/v2/views

     1  // Copyright 2016 The Tcell Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use file except in compliance with the License.
     5  // You may obtain a copy of the license at
     6  //
     7  //    http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package views
    16  
    17  import (
    18  	"strings"
    19  	"sync"
    20  
    21  	"github.com/gdamore/tcell/v2"
    22  )
    23  
    24  // TextArea is a pannable 2 dimensional text widget. It wraps both
    25  // the view and the model for text in a single, convenient widget.
    26  // Text is provided as an array of strings, each of which represents
    27  // a single line to display.  All text in the TextArea has the same
    28  // style.  An optional soft cursor is available.
    29  type TextArea struct {
    30  	model *linesModel
    31  	once  sync.Once
    32  	CellView
    33  }
    34  
    35  type linesModel struct {
    36  	runes  [][]rune
    37  	width  int
    38  	height int
    39  	x      int
    40  	y      int
    41  	hide   bool
    42  	cursor bool
    43  	style  tcell.Style
    44  }
    45  
    46  func (m *linesModel) GetCell(x, y int) (rune, tcell.Style, []rune, int) {
    47  	if x < 0 || y < 0 || y >= m.height || x >= len(m.runes[y]) {
    48  		return 0, m.style, nil, 1
    49  	}
    50  	// XXX: extend this to support combining and full width chars
    51  	return m.runes[y][x], m.style, nil, 1
    52  }
    53  
    54  func (m *linesModel) GetBounds() (int, int) {
    55  	return m.width, m.height
    56  }
    57  
    58  func (m *linesModel) limitCursor() {
    59  	if m.x > m.width-1 {
    60  		m.x = m.width - 1
    61  	}
    62  	if m.y > m.height-1 {
    63  		m.y = m.height - 1
    64  	}
    65  	if m.x < 0 {
    66  		m.x = 0
    67  	}
    68  	if m.y < 0 {
    69  		m.y = 0
    70  	}
    71  }
    72  
    73  func (m *linesModel) SetCursor(x, y int) {
    74  	m.x = x
    75  	m.y = y
    76  	m.limitCursor()
    77  }
    78  
    79  func (m *linesModel) MoveCursor(x, y int) {
    80  	m.x += x
    81  	m.y += y
    82  	m.limitCursor()
    83  }
    84  
    85  func (m *linesModel) GetCursor() (int, int, bool, bool) {
    86  	return m.x, m.y, m.cursor, !m.hide
    87  }
    88  
    89  // SetLines sets the content text to display.
    90  func (ta *TextArea) SetLines(lines []string) {
    91  	ta.Init()
    92  	m := ta.model
    93  	m.width = 0
    94  
    95  	// extend slice before using m.runes[row] to avoid panic
    96  	slice := make([][]rune, len(lines))
    97  	m.runes = slice
    98  
    99  	for row, line := range lines {
   100  		for _, ch := range line {
   101  			m.runes[row] = append(m.runes[row], ch)
   102  		}
   103  		if len(m.runes[row]) > m.width {
   104  			m.width = len(m.runes[row])
   105  		}
   106  	}
   107  
   108  	m.height = len(m.runes)
   109  
   110  	ta.CellView.SetModel(m)
   111  }
   112  
   113  func (ta *TextArea) SetStyle(style tcell.Style) {
   114  	ta.model.style = style
   115  	ta.CellView.SetStyle(style)
   116  }
   117  
   118  // EnableCursor enables a soft cursor in the TextArea.
   119  func (ta *TextArea) EnableCursor(on bool) {
   120  	ta.Init()
   121  	ta.model.cursor = on
   122  }
   123  
   124  // HideCursor hides or shows the cursor in the TextArea.
   125  // If on is true, the cursor is hidden.  Note that a cursor is only
   126  // shown if it is enabled.
   127  func (ta *TextArea) HideCursor(on bool) {
   128  	ta.Init()
   129  	ta.model.hide = on
   130  }
   131  
   132  // SetContent is used to set the textual content, passed as a
   133  // single string.  Lines within the string are delimited by newlines.
   134  func (ta *TextArea) SetContent(text string) {
   135  	ta.Init()
   136  	lines := strings.Split(strings.Trim(text, "\n"), "\n")
   137  	ta.SetLines(lines)
   138  }
   139  
   140  // Init initializes the TextArea.
   141  func (ta *TextArea) Init() {
   142  	ta.once.Do(func() {
   143  		lm := &linesModel{runes: [][]rune{}, width: 0}
   144  		ta.model = lm
   145  		ta.CellView.Init()
   146  		ta.CellView.SetModel(lm)
   147  	})
   148  }
   149  
   150  // NewTextArea creates a blank TextArea.
   151  func NewTextArea() *TextArea {
   152  	ta := &TextArea{}
   153  	ta.Init()
   154  	return ta
   155  }
   156
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