path: root/doc/qtcreator/src/qtquick/library/qtquick-text.qdoc

/****************************************************************************
**
** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Creator documentation.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Free Documentation License Usage
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file. Please review the following information to ensure
** the GNU Free Documentation License version 1.3 requirements
** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
**
****************************************************************************/

/*!
    \page quick-text.html
    \previouspage quick-shapes.html
    \nextpage quick-images.html

    \title Text

    You can use several different text types to add read-only or editable text
    to a UI, such as titles or labels and text input fields with placeholder
    text. The \l Text type adds formatted text, the \l TextEdit type adds a
    multiline line edit, and the \l TextInput type adds a single editable line
    field.

    You can select the font to use and specify extensive properties for each
    text string, such as size in points or pixels, style name, emphasis,
    alignment, and spacing.

    For an example of editing the Text type, watch
    \l{https://www.youtube.com/watch?v=yOUdg1o2KJM}
    {Qt Design Studio QuickTip: Text Element}.

    To create a label with a background, use the \l Label type from the
    Qt Quick Controls module.

    \section1 Typography

    For each string that you enter in the \uicontrol Text field, you can
    select the font to use in the \uicontrol Font field and specify the
    size, emphasis, aligment, and spacing of the text. Specify the font
    size in either points or pixels in the \uicontrol Size field.

    \image qtquick-designer-text-properties.png "Text type properties"

    To display custom fonts in the list of available fonts in the
    \uicontrol Font field, add them in the \uicontrol Assets tab
    of \uicontrol Library. For more information, see \l {Assets}.

    You can use the buttons in the \uicontrol {Font style} group to emphasize
    text by making it bold, italic, underlined, or strikethrough.

    Alternatively, select a font variant to use in the \uicontrol {Style name}
    field, such as \uicontrol Regular or \uicontrol Bold.

    The value of the \uicontrol Word field in the \uicontrol Spacing group
    changes the default spacing between individual words, whereas the value
    of the \uicontrol Letter field changes the spacing between individual
    letters in a word. A positive value increases the spacing by a
    corresponding amount of pixels, while a negative value decreases it.

    The value of the \uicontrol {Line height} field sets the line height
    for the text. In the \uicontrol {Line height mode} field, select
    \uicontrol FixedHeight to set the line height in pixels or
    \uicontrol ProportionalHeight (default) to set the spacing proportionally
    to the line (as a multiplier). For example, set to 2 for double spacing.

    \section1 Text Alignment

    You can align text items horizontally and vertically. By default, text is
    vertically aligned to the top. Horizontal alignment follows the natural
    alignment of the text. By default, left-to-right text like English is
    aligned to the left side of the text area, whereas right-to-left text
    like Arabic is aligned to the right side of the text area.

    You can align text to the left, right, top, or bottom, and center it
    horizontally or vertically. You can justify horizontal text.

    For a single line of text, the size of the text is the area of the text.
    In this common case, all alignments are equivalent. To center a text in
    its parent, use \l{Setting Anchors and Margins}{anchoring} or bind the
    width of the text item to that of the parent. For more information, see
    \l{Setting Bindings}.

    \section1 Text and Style Colors

    You can set the color of the text itself and a secondary color used by
    text styles.

    The color that you pick in the \uicontrol {Style color} field is used as
    the outline color for outlined text, and as the shadow color for raised
    or sunken text. You set the font style in the \uicontrol Style field of
    the \uicontrol Font section.

    For the \uicontrol {Text Edit} and \uicontrol {Text Input} types, you
    can also set the color of selected text and the text highlight color
    that is used behind selections in the \uicontrol {Selected text color}
    and \uicontrol {Selection color} fields.

    For more information about selecting colors, see \l{Picking Colors}. You
    can only set solid colors for text items.

    \section1 Advanced Text Properties

    The height and width of a text item are determined automatically depending
    on the values of the properties you set, to accommodate the length of the
    string that you specify in the \uicontrol Text field and the font size, for
    example.

    The value of the \uicontrol {Font size mode} field specifies how the font
    size of the displayed text is determined. Select \uicontrol FixedSize to
    use the size specified in the \uicontrol Size field in pixels or points.
    Select \uicontrol HorizontalFit or \uicontrol VerticalFit to use the largest
    size up to the size specified that fits the width or height of the item.
    Select \uicontrol Fit to use the largest size up to the size specified that
    fits within the width and height of the item. The font size of fitted text
    has a minimum bound specified by the \uicontrol {Minimum size} field and
    maximum bound specified by the \uicontrol Size field.

    In the \uicontrol {Wrap mode} field, you can wrap the text to the text
    item's width. The text will only wrap if you set an explicit width for
    the text item. By default, text is not wrapped. Select \uicontrol WordWrap
    to restrict wrapping to word boundaries only. Select \uicontrol WrapAnywhere
    to enable wrapping at any point on a line, even if it occurs in the middle
    of a word. Select \uicontrol Wrap to wrap at a word boundary, if possible,
    or at the appropriate point on the line, even in the middle of a word.

    You can use the \uicontrol Elide property with the \uicontrol Wrap
    option to fit a single line of plain text to a set width. Select
    \uicontrol ElideRight, and set the \uicontrol {Maximum line count}
    or the text item height (in the \uicontrol H field). If you set both,
    the maximum line count will apply unless the lines do not fit in the
    height allowed.

    If the text is a multi-length string, and you set the \uicontrol Elide
    property value to something else than \uicontrol ElideNone, the first
    string that fits will be used, otherwise the last will be elided.

    Multi-length strings are ordered from longest to shortest, separated by the
    Unicode \e {String Terminator} character \c U009C.

    \section1 Advanced Font Properties

    In the \uicontrol {Font weight} field, you can select the font weight from
    list predefined values that range between extra-light and extra-bold.

    In the \uicontrol {Font capitalization} field, select \uicontrol MixedCase
    for normal text rendering where no capitalization changes are applied. You
    can also set the text in all upper or lower case, or use small caps. The
    \uicontrol Capitalize option renders the first character of each word as an
    uppercase character.

    \section1 Developer Text Properties

    Text can be either in plain text or rich text format, depending on the
    value you set in the \uicontrol Format field. If you select
    \uicontrol AutoText and the the first line of text contains an HTML tag,
    the text is treated as rich text. Rich text supports a subset of HTML 4
    described on the \l {Supported HTML Subset}. Note that plain text offers
    better performance than rich text.

    In the \uicontrol {Render type} field, you can override the default
    rendering type for a text item. Select \uicontrol NativeRendering if
    you prefer text to look native on the target platform and do not
    require advanced features such as \l {Managing 2D Transformations}
    {transformation} of the text. Using rotation or scaling in combination
    with native rendering leads to poor and sometimes pixelated results.

    \section1 Text Input

    You can use the \uicontrol {Text Edit} and \uicontrol {Text Input} types to
    add text fields where users can enter text.

    The Text Input type displays a single line of editable plain text, whereas
    the Text Edit type displays a block of editable, formatted text. Both types
    are used to accept text input.

    \image qtquick-designer-text-input-properties.png "Text input field properties"

    In the \uicontrol {Mouse selection mode} field, you can specify whether
    individual characters or whole words are selected when selecting text.

    In the \uicontrol {Input mask} field, you can create an input mask that
    contains mask and meta characters and separators between them. When created
    or cleared, the text edit or input is filled with a copy of the input mask
    string, where the meta characters have been removed, and the mask characters
    have been replaced with the blank character. For example, in an input field
    for an IP address, you could use the following mask (with the underscore as
    the blank character): \c {000.000.000.000;_}. For more information about
    creating input masks, see the documentation for \l QLineEdit::inputMask.

    In the \uicontrol {Echo mode} field, select \uicontrol Password to display
    platform-dependent password mask characters instead of the actual characters
    that users enter. Select \uicontrol PasswordEchoOnEdit to display characters
    as users enter them. The mask character is displayed in the
    \uicontrol {Pass. char} field.

    In the \uicontrol {Maximum length} field, set the maximum number of
    characters that users can enter.

    The value of the \uicontrol {Auto scroll} check box determines whether the
    text edit or input should scroll when the text is longer than the width of
    the input field.

    If the \uicontrol {Overwrite mode} check box is selected, existing text is
    overwritten, character-for-character by new text. Otherwise, new text is
    inserted at the cursor position, displacing existing text. By default, new
    text does not overwrite existing text.

    To prevent users from changing the text, select the \uicontrol {Read only}
    check box.

    The value of the \uicontrol {Set active focus on press} check box determines
    whether the text edit or input should gain active focus on a mouse press.

    By default, the cursor becomes visible when the text edit or input gains
    active focus, so that other properties can be bound to whether the cursor
    is currently shown. Because the value of the \uicontrol {Cursor visible}
    property gets set and unset automatically, any value you set yourself may
    be overwritten.

    If the \uicontrol {Persistent selection} check box is selected, a text edit
    or input keeps its selection when active focus moves to another item.

    To use a pointer device for selecting text, select the
    \uicontrol {Select by mouse} check box.

    \section1 Padding

    The values of the properties in the \uicontrol Padding section specify the
    padding around the content. The individual padding properties adopt the
    value of the \uicontrol Padding field, unless you set them explicitly.

    \note If you explicitly set the width or height of a text edit or input,
    ensure that it is large enough to accommodate the padding values. If the
    text does not have enough vertical or horizontal space in which to be
    rendered, it will appear clipped.

    \section1 Summary of Text Components

    The following table lists the QML types that you can use to add text to
    UIs. The \e Location column contains the tab name where you can find the
    type in \uicontrol Library. The \e MCU column indicates which types are
    supported on MCUs.

    \table
    \header
        \li Icon
        \li Name
        \li Location
        \li MCU
        \li Purpose
    \row
        \li \inlineimage icons/label-icon16.png
        \li \l [QtQuickControls]{Label}
        \li Qt Quick - Controls 2
        \li
        \li A text label with inherited styling and font.
    \row
        \li \inlineimage text-icon16.png
        \li \l [QtQuick]{Text}
        \li Qt Quick - Basic
        \li \inlineimage ok
        \li Formatted read-only text.
    \row
        \li \inlineimage icons/textarea-icon16.png
        \li \l [QtQuickControls]{TextArea}{Text Area}
        \li Qt Quick - Controls 2
        \li
        \li Multiple lines of editable formatted text.
    \row
        \li \inlineimage text-edit-icon16.png
        \li \l [QtQuick]{TextEdit}{Text Edit}
        \li Qt Quick - Basic
        \li
        \li A single line of editable formatted text that can be validated.
    \row
        \li \inlineimage icons/textfield-icon16.png
        \li \l [QtQuickControls]{TextField}{Text Field}
        \li Qt Quick - Controls 2
        \li
        \li A single line of editable plain text.
    \row
        \li \inlineimage text-input-icon16.png
        \li \l [QtQuick]{TextInput}{Text Input}
        \li Qt Quick - Basic
        \li
        \li A single line of editable plain text that can be validated.
    \endtable
*/