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Diffstat (limited to 'vendor/maunium.net/go/tview/form.go')
| -rw-r--r-- | vendor/maunium.net/go/tview/form.go | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/vendor/maunium.net/go/tview/form.go b/vendor/maunium.net/go/tview/form.go new file mode 100644 index 0000000..b1e8f5e --- /dev/null +++ b/vendor/maunium.net/go/tview/form.go @@ -0,0 +1,499 @@ +package tview + +import ( + "strings" + + "maunium.net/go/tcell" +) + +// DefaultFormFieldWidth is the default field screen width of form elements +// whose field width is flexible (0). This is used in the Form class for +// horizontal layouts. +var DefaultFormFieldWidth = 10 + +// FormItem is the interface all form items must implement to be able to be +// included in a form. +type FormItem interface { + Primitive + + // GetLabel returns the item's label text. + GetLabel() string + + // SetFormAttributes sets a number of item attributes at once. + SetFormAttributes(label string, labelColor, bgColor, fieldTextColor, fieldBgColor tcell.Color) FormItem + + // GetFieldWidth returns the width of the form item's field (the area which + // is manipulated by the user) in number of screen cells. A value of 0 + // indicates the the field width is flexible and may use as much space as + // required. + GetFieldWidth() int + + // SetEnteredFunc sets the handler function for when the user finished + // entering data into the item. The handler may receive events for the + // Enter key (we're done), the Escape key (cancel input), the Tab key (move to + // next field), and the Backtab key (move to previous field). + SetFinishedFunc(handler func(key tcell.Key)) FormItem +} + +// Form allows you to combine multiple one-line form elements into a vertical +// or horizontal layout. Form elements include types such as InputField or +// Checkbox. These elements can be optionally followed by one or more buttons +// for which you can define form-wide actions (e.g. Save, Clear, Cancel). +// +// See https://github.com/rivo/tview/wiki/Form for an example. +type Form struct { + *Box + + // The items of the form (one row per item). + items []FormItem + + // The buttons of the form. + buttons []*Button + + // If set to true, instead of position items and buttons from top to bottom, + // they are positioned from left to right. + horizontal bool + + // The alignment of the buttons. + buttonsAlign int + + // The number of empty rows between items. + itemPadding int + + // The index of the item or button which has focus. (Items are counted first, + // buttons are counted last.) + focusedElement int + + // The label color. + labelColor tcell.Color + + // The background color of the input area. + fieldBackgroundColor tcell.Color + + // The text color of the input area. + fieldTextColor tcell.Color + + // The background color of the buttons. + buttonBackgroundColor tcell.Color + + // The color of the button text. + buttonTextColor tcell.Color + + // An optional function which is called when the user hits Escape. + cancel func() +} + +// NewForm returns a new form. +func NewForm() *Form { + box := NewBox().SetBorderPadding(1, 1, 1, 1) + + f := &Form{ + Box: box, + itemPadding: 1, + labelColor: Styles.SecondaryTextColor, + fieldBackgroundColor: Styles.ContrastBackgroundColor, + fieldTextColor: Styles.PrimaryTextColor, + buttonBackgroundColor: Styles.ContrastBackgroundColor, + buttonTextColor: Styles.PrimaryTextColor, + } + + f.focus = f + + return f +} + +// SetItemPadding sets the number of empty rows between form items for vertical +// layouts and the number of empty cells between form items for horizontal +// layouts. +func (f *Form) SetItemPadding(padding int) *Form { + f.itemPadding = padding + return f +} + +// SetHorizontal sets the direction the form elements are laid out. If set to +// true, instead of positioning them from top to bottom (the default), they are +// positioned from left to right, moving into the next row if there is not +// enough space. +func (f *Form) SetHorizontal(horizontal bool) *Form { + f.horizontal = horizontal + return f +} + +// SetLabelColor sets the color of the labels. +func (f *Form) SetLabelColor(color tcell.Color) *Form { + f.labelColor = color + return f +} + +// SetFieldBackgroundColor sets the background color of the input areas. +func (f *Form) SetFieldBackgroundColor(color tcell.Color) *Form { + f.fieldBackgroundColor = color + return f +} + +// SetFieldTextColor sets the text color of the input areas. +func (f *Form) SetFieldTextColor(color tcell.Color) *Form { + f.fieldTextColor = color + return f +} + +// SetButtonsAlign sets how the buttons align horizontally, one of AlignLeft +// (the default), AlignCenter, and AlignRight. This is only +func (f *Form) SetButtonsAlign(align int) *Form { + f.buttonsAlign = align + return f +} + +// SetButtonBackgroundColor sets the background color of the buttons. +func (f *Form) SetButtonBackgroundColor(color tcell.Color) *Form { + f.buttonBackgroundColor = color + return f +} + +// SetButtonTextColor sets the color of the button texts. +func (f *Form) SetButtonTextColor(color tcell.Color) *Form { + f.buttonTextColor = color + return f +} + +// AddInputField adds an input field to the form. It has a label, an optional +// initial value, a field width (a value of 0 extends it as far as possible), +// an optional accept function to validate the item's value (set to nil to +// accept any text), and an (optional) callback function which is invoked when +// the input field's text has changed. +func (f *Form) AddInputField(label, value string, fieldWidth int, accept func(textToCheck string, lastChar rune) bool, changed func(text string)) *Form { + f.items = append(f.items, NewInputField(). + SetLabel(label). + SetText(value). + SetFieldWidth(fieldWidth). + SetAcceptanceFunc(accept). + SetChangedFunc(changed)) + return f +} + +// AddPasswordField adds a password field to the form. This is similar to an +// input field except that the user's input not shown. Instead, a "mask" +// character is displayed. The password field has a label, an optional initial +// value, a field width (a value of 0 extends it as far as possible), and an +// (optional) callback function which is invoked when the input field's text has +// changed. +func (f *Form) AddPasswordField(label, value string, fieldWidth int, mask rune, changed func(text string)) *Form { + if mask == 0 { + mask = '*' + } + f.items = append(f.items, NewInputField(). + SetLabel(label). + SetText(value). + SetFieldWidth(fieldWidth). + SetMaskCharacter(mask). + SetChangedFunc(changed)) + return f +} + +// AddDropDown adds a drop-down element to the form. It has a label, options, +// and an (optional) callback function which is invoked when an option was +// selected. The initial option may be a negative value to indicate that no +// option is currently selected. +func (f *Form) AddDropDown(label string, options []string, initialOption int, selected func(option string, optionIndex int)) *Form { + f.items = append(f.items, NewDropDown(). + SetLabel(label). + SetCurrentOption(initialOption). + SetOptions(options, selected)) + return f +} + +// AddCheckbox adds a checkbox to the form. It has a label, an initial state, +// and an (optional) callback function which is invoked when the state of the +// checkbox was changed by the user. +func (f *Form) AddCheckbox(label string, checked bool, changed func(checked bool)) *Form { + f.items = append(f.items, NewCheckbox(). + SetLabel(label). + SetChecked(checked). + SetChangedFunc(changed)) + return f +} + +// AddButton adds a new button to the form. The "selected" function is called +// when the user selects this button. It may be nil. +func (f *Form) AddButton(label string, selected func()) *Form { + f.buttons = append(f.buttons, NewButton(label).SetSelectedFunc(selected)) + return f +} + +// Clear removes all input elements from the form, including the buttons if +// specified. +func (f *Form) Clear(includeButtons bool) *Form { + f.items = nil + if includeButtons { + f.buttons = nil + } + f.focusedElement = 0 + return f +} + +// AddFormItem adds a new item to the form. This can be used to add your own +// objects to the form. Note, however, that the Form class will override some +// of its attributes to make it work in the form context. +func (f *Form) AddFormItem(item FormItem) *Form { + f.items = append(f.items, item) + return f +} + +// GetFormItem returns the form element at the given position, starting with +// index 0. Elements are referenced in the order they were added. Buttons are +// not included. +func (f *Form) GetFormItem(index int) FormItem { + return f.items[index] +} + +// SetCancelFunc sets a handler which is called when the user hits the Escape +// key. +func (f *Form) SetCancelFunc(callback func()) *Form { + f.cancel = callback + return f +} + +// Draw draws this primitive onto the screen. +func (f *Form) Draw(screen tcell.Screen) { + f.Box.Draw(screen) + + // Determine the dimensions. + x, y, width, height := f.GetInnerRect() + topLimit := y + bottomLimit := y + height + rightLimit := x + width + startX := x + + // Find the longest label. + var maxLabelWidth int + for _, item := range f.items { + label := strings.TrimSpace(item.GetLabel()) + labelWidth := StringWidth(label) + if labelWidth > maxLabelWidth { + maxLabelWidth = labelWidth + } + } + maxLabelWidth++ // Add one space. + + // Calculate positions of form items. + positions := make([]struct{ x, y, width, height int }, len(f.items)+len(f.buttons)) + var focusedPosition struct{ x, y, width, height int } + for index, item := range f.items { + // Calculate the space needed. + label := strings.TrimSpace(item.GetLabel()) + labelWidth := StringWidth(label) + var itemWidth int + if f.horizontal { + fieldWidth := item.GetFieldWidth() + if fieldWidth == 0 { + fieldWidth = DefaultFormFieldWidth + } + label += " " + labelWidth++ + itemWidth = labelWidth + fieldWidth + } else { + // We want all fields to align vertically. + label += strings.Repeat(" ", maxLabelWidth-labelWidth) + itemWidth = width + } + + // Advance to next line if there is no space. + if f.horizontal && x+labelWidth+1 >= rightLimit { + x = startX + y += 2 + } + + // Adjust the item's attributes. + if x+itemWidth >= rightLimit { + itemWidth = rightLimit - x + } + item.SetFormAttributes( + label, + f.labelColor, + f.backgroundColor, + f.fieldTextColor, + f.fieldBackgroundColor, + ) + + // Save position. + positions[index].x = x + positions[index].y = y + positions[index].width = itemWidth + positions[index].height = 1 + if item.GetFocusable().HasFocus() { + focusedPosition = positions[index] + } + + // Advance to next item. + if f.horizontal { + x += itemWidth + f.itemPadding + } else { + y += 1 + f.itemPadding + } + } + + // How wide are the buttons? + buttonWidths := make([]int, len(f.buttons)) + buttonsWidth := 0 + for index, button := range f.buttons { + w := StringWidth(button.GetLabel()) + 4 + buttonWidths[index] = w + buttonsWidth += w + 1 + } + buttonsWidth-- + + // Where do we place them? + if !f.horizontal && x+buttonsWidth < rightLimit { + if f.buttonsAlign == AlignRight { + x = rightLimit - buttonsWidth + } else if f.buttonsAlign == AlignCenter { + x = (x + rightLimit - buttonsWidth) / 2 + } + + // In vertical layouts, buttons always appear after an empty line. + if f.itemPadding == 0 { + y++ + } + } + + // Calculate positions of buttons. + for index, button := range f.buttons { + space := rightLimit - x + buttonWidth := buttonWidths[index] + if f.horizontal { + if space < buttonWidth-4 { + x = startX + y += 2 + space = width + } + } else { + if space < 1 { + break // No space for this button anymore. + } + } + if buttonWidth > space { + buttonWidth = space + } + button.SetLabelColor(f.buttonTextColor). + SetLabelColorActivated(f.buttonBackgroundColor). + SetBackgroundColorActivated(f.buttonTextColor). + SetBackgroundColor(f.buttonBackgroundColor) + + buttonIndex := index + len(f.items) + positions[buttonIndex].x = x + positions[buttonIndex].y = y + positions[buttonIndex].width = buttonWidth + positions[buttonIndex].height = 1 + + if button.HasFocus() { + focusedPosition = positions[buttonIndex] + } + + x += buttonWidth + 1 + } + + // Determine vertical offset based on the position of the focused item. + var offset int + if focusedPosition.y+focusedPosition.height > bottomLimit { + offset = focusedPosition.y + focusedPosition.height - bottomLimit + if focusedPosition.y-offset < topLimit { + offset = focusedPosition.y - topLimit + } + } + + // Draw items. + for index, item := range f.items { + // Set position. + y := positions[index].y - offset + height := positions[index].height + item.SetRect(positions[index].x, y, positions[index].width, height) + + // Is this item visible? + if y+height <= topLimit || y >= bottomLimit { + continue + } + + // Draw items with focus last (in case of overlaps). + if item.GetFocusable().HasFocus() { + defer item.Draw(screen) + } else { + item.Draw(screen) + } + } + + // Draw buttons. + for index, button := range f.buttons { + // Set position. + buttonIndex := index + len(f.items) + y := positions[buttonIndex].y - offset + height := positions[buttonIndex].height + button.SetRect(positions[buttonIndex].x, y, positions[buttonIndex].width, height) + + // Is this button visible? + if y+height <= topLimit || y >= bottomLimit { + continue + } + + // Draw button. + button.Draw(screen) + } +} + +// Focus is called by the application when the primitive receives focus. +func (f *Form) Focus(delegate func(p Primitive)) { + if len(f.items)+len(f.buttons) == 0 { + return + } + + // Hand on the focus to one of our child elements. + if f.focusedElement < 0 || f.focusedElement >= len(f.items)+len(f.buttons) { + f.focusedElement = 0 + } + handler := func(key tcell.Key) { + switch key { + case tcell.KeyTab, tcell.KeyEnter: + f.focusedElement++ + f.Focus(delegate) + case tcell.KeyBacktab: + f.focusedElement-- + if f.focusedElement < 0 { + f.focusedElement = len(f.items) + len(f.buttons) - 1 + } + f.Focus(delegate) + case tcell.KeyEscape: + if f.cancel != nil { + f.cancel() + } else { + f.focusedElement = 0 + f.Focus(delegate) + } + } + } + + if f.focusedElement < len(f.items) { + // We're selecting an item. + item := f.items[f.focusedElement] + item.SetFinishedFunc(handler) + delegate(item) + } else { + // We're selecting a button. + button := f.buttons[f.focusedElement-len(f.items)] + button.SetBlurFunc(handler) + delegate(button) + } +} + +// HasFocus returns whether or not this primitive has focus. +func (f *Form) HasFocus() bool { + for _, item := range f.items { + if item.GetFocusable().HasFocus() { + return true + } + } + for _, button := range f.buttons { + if button.focus.HasFocus() { + return true + } + } + return false +} |