APL Text (APL 1.7 to 2024.1)
(This is not the most recent version of APL. Use the Other Versions option to see the documentation for the most recent version of APL)
The Text component displays text in either a single line or multiple lines.
Properties
The Text component has the following properties in addition to the base component properties. See the meaning of the columns.
Property | Type | Default | Styled | Dynamic | Description |
---|---|---|---|---|---|
|
depends on the theme |
Yes |
Yes |
The color of the text. | |
|
String |
sans-serif |
Yes |
Yes |
Font family (such as "Amazon Ember Display"). |
|
Non-negative absolute Dimension |
40dp |
Yes |
Yes |
The size of the text. |
|
|
normal |
Yes |
Yes |
The font style to display. |
|
|
normal |
Yes |
Yes |
The font weight to display. |
|
String |
"" |
Yes |
Yes |
The language of the text. When set, APL attempts to find a language-specific version of the |
|
Absolute Dimension |
0 |
Yes |
No |
Additional space to add between letters. |
|
Number (percentage) |
125% |
Yes |
No |
Line-height multiplier. |
|
Non-negative integer |
0 |
Yes |
No |
The maximum number of lines of text to display. The text will be truncated with an ellipsis if not all text is visible. |
|
String |
"" |
No |
Yes |
The markup to display in this text box. If this value is set to |
|
|
auto |
Yes |
No |
Alignment of text within a paragraph. |
|
|
auto |
Yes |
No |
Vertical alignment of text. |
Most of these properties have default values specified by the current text style. Refer to Resources for a discussion of styles.
A Text component doesn't scroll unless it's within a ScrollView.
When the Text
is the source or target of an event, the following values are reported in event.source
or event.target
:
{
// Text-specific values
"type": "Text",
"text": String, // Displayed text
"color": Color, // The text color
// General component values
"bind": Map, // Access to component data-binding context
"checked": Boolean, // Checked state
"disabled": Boolean, // Disabled state
"focused": Boolean, // Focused state
"height": Number, // Height of the component, in dp (includes the padding)
"id": ID, // ID of the component
"opacity": Number, // Opacity of the component [0-1]
"pressed": Boolean, // Pressed state
"uid": UID, // Runtime-generated unique ID of the component
"width": Number // Width of the component, in dp (includes the padding)
}
layoutDirection component property
The component layoutDirection
property determines how the Text
component interprets the textAlign
property for aligning text.
height and width component properties
The component properties for height
and width
control the size of the bounding box for a Text
component. When the bounding box is too small for the text to display, the device truncates the text and displays an ellipsis to indicate that not all text is displayed.
For details about the component height
and width
properties, see APL Base Component Properties.
For details and examples of the text bounding box, see Understand the bounding box for the Text component.
color
The color of the text. If the theme is light, the default is #1E2222
. If the theme is dark, the default is #FAFAFA
.
fontFamily
Specifies the font for the displayed text. The fontFamily
property takes a single font name or a string containing a comma-separated list of font names. The APL runtime searches the list for the first named font installed on the device. If no valid font is found, the runtime defaults to the sans-serif font.
Font names can contain spaces. APL supports two types of font names:
- The specific name of an installed font such as "amazon-ember", "times", "times new roman".
- A generic name - either "serif" or "sans-serif".
Alexa devices don't guarantee a specific set of fonts. End your fontFamily
list with either "serif" or "sans-serif" to make sure that a valid font is available.
{
"type": "Text",
"fontFamily", "times new roman, times, georgia, serif"
}
On many Alexa devices, "sans-serif" defaults to "Amazon Ember Display" and "serif" defaults to "Bookerly". In some Asian markets they default to "Noto Sans CJK".
For details about font styles available in the alexa-styles
package, see Font family.
fontSize
The size of the font, normally expressed in dp. The default is 40dp
.
fontStyle
The style of the font, either normal
or italic
. Defaults to normal
.
fontWeight
The font weight for the displayed text. Defaults to normal
. The normal
and bold
values are assigned at runtime. The integer values 100 through 900 correspond to progressively darker variations of the font. Most fonts don't support this many variations. For example, Amazon Ember Display has five weights (Thin, Light, Regular, Medium, Bold) which are assigned 100, 300, 500, 700, and 900 respectively.
Note that fontWeight
represents an enumerated set, not integers or strings. For example, the value 750 is invalid and doesn't set the font to a weight between 700 and 800.
When you create a resource for a fontWeight
, use a string
resource. The following example resource block creates two resources for fontWeight
called myMidFontWeight
and myLightFontWeight
.
{
"resources": [
{
"strings": {
"myMidFontWeight": "500",
"myLightFontWeight": "100"
}
}
]
}
lang
The language of the text. When set, APL attempts to find a language-specific version of the fontFamily
for displaying the text.
If no valid font is found, APL ignores this property and uses the specified fontFamily
.
Set the lang
property to a BCP-47 string (for example, "en-US").
The following example displays a Text
component with a Japanese-style version of the NotoSans-CJK font:
{
"type": "APL",
"version": "2024.2",
"mainTemplate": {
"item": {
"type": "Text",
"lang": "ja-JP",
"fontFamily": "Noto Sans CJK"
}
}
}
Note: Alexa devices might not have the font in specific language installed. Test the experience on the device or devices to confirm that it works.
letterSpacing
Additional space to add between letters. Defaults to 0.
lineHeight
Line-height multiplier. Defaults to 125%.
The leading of the font is the fontSize
multiplied by the lineHeight
. For
example, on a 320 dpi display with 100dp fontSize
and 120% lineHeight
, the font size is 200 pixels and the leading is
240 pixels. Setting the lineHeight
to less than 100% can
cause characters to overlap.
maxLines
The maximum number of lines of text to display. Defaults to 0, which indicates no maximum. Set to a positive integer to clip the text to the specified number of lines and insert an ellipsis to show that the text is truncated.
text
Text string to display in the text block. If set to an empty string, no text displays. Setting to null
is equivalent to an empty string (""
).
Text blocks support simple markup. Supported tags include:
Tag | Description | Example | Display |
---|---|---|---|
|
Insert a line break. Line breaks may be repeated. |
Line 1 |
Line 1 |
|
Bold a span of text. (font weight 700). |
|
Large dogs are friendly. |
|
Italic a span of text. |
Read |
Read Emma for homework. |
|
|
The document is |
The document is |
|
Underline a span of text |
I just |
I just loved the chocolate! |
|
Monospace a span of text. |
The |
The |
|
Superscript and subscript a span of text. |
See Gibson |
See Gibson1 for the H2O formula. |
|
Prevent text from automatically wrapping across multiple lines |
Avoid breaking <nobr>Dr. A. Ramaswamy</nobr> and treat it as one whole word. |
Avoid breaking
Dr. A. Ramaswamy and treat it as one whole word. |
|
Define a span to apply inline formatting. See Supported span attributes. |
|
This is RED |
You can nest markup elements. Improperly nested markup gives undefined behavior. For example, the following code might not render correctly because the <b>
and <u>
elements aren't nested correctly.
<b>Once upon a time, <u>a small dog</b> ate a grasshopper and felt ill.</u>.
The following example shows the use of text markup.
Markup characters in text must be replaced with character entity references.
Entity | Character | Description |
---|---|---|
|
& |
Ampersand |
|
< |
Less-than |
|
> |
Greater-than |
|
Any Decimal Unicode code-point. |
" |
|
Hexadecimal Unicode code-point. |
" |
Numeric entity references can be in decimal or hexadecimal. For example, © can be written ©
or ©
.
Supported span attributes
The <span>
tag supports the named attributes shown in the following table.
Attribute | Description | Example | Display |
---|---|---|---|
|
Color of the text span. Can be any color. You can specify the color using a resource. Set to |
|
This is RED |
|
Font size for the text span. Must be a non-negative absolute dimension. You can set the dimension using a resource. Set to |
|
This is BIG |
textAlign
Controls the horizontal alignment for lines of text. Set to one of the following:
auto
(default)left
center
right
start
end
The auto
, start
, and end
properties all align the text based on the specified layoutDirection
for the component:
Property | Left-to-right ("LTR") | Right-to-left ("RTL") |
---|---|---|
|
Left-aligns text |
Right-aligns text |
|
Left-aligns text |
Right-aligns text |
|
Right-aligns text |
Left-aligns text |
textAlignVertical
Positions the text within the text box. Only used if the text box is taller than the text content. Defaults to top
.
Sample text
The following example shows a Text
component that displays the provided text
in green. The example uses a conditional statement for the maxLines
property to truncate the text on small, round hubs, but show the full text on larger devices.
Related topics
Last updated: Jan 08, 2024