Kotlin wrappers around SpannableStringBuilder. Inspired by binaryfork's Spanny.
SpannableStringBuilder API is attractive, it's a nice way to styling text without split your text into multiple views, but the usage of the raw API is awful.
Let's say a simple example: Spans are hard?
- The raw
SpannableStringBuilderAPI:
val builder = SpannableStringBuilder()
builder.append("Spans ")
var str = "are "
builder.append(str)
builder.setSpan(StyleSpan(Typeface.BOLD), builder.length - str.length, builder.length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
str = "hard"
builder.append(str)
builder.setSpan(StyleSpan(Typeface.BOLD), builder.length - str.length, builder.length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
builder.setSpan(StrikethroughSpan(), builder.length - str.length, builder.length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
builder.append("?")- The Spanny helper API:
val spanny = Spanny("Spans ")
.append("are ", StyleSpan(Typeface.BOLD))
.append("hard", StyleSpan(Typeface.BOLD), StrikethroughSpan())
.append("?")That is cool in Java, but I was using kotlin, and it's not cool enough, it's verbose and limited. Kotlin allows to type-check builders, which is the best way to build spans, so I make it happen:
val text = span {
+"Spans "
span {
textStyle = "bold"
+"are "
span("hard") {
textDecorationLine = "line-through"
}
}
+"?"
}
You can grab it via Gradle:
implementation 'me.gujun.android:span:1.3'
val text = span {
textColor = Color.BLACK
backgroundColor = Color.WHITE
textSize = dp(13)
fontFamily = "monospace"
typeface = getFont(R.font.pacifico)
textStyle = "bold"
alignment = "normal"
textDecorationLine = "underline"
lineSpacing = dp(3)
verticalPadding = dp(5)
paddingTop = dp(5)
paddingBottom = dp(5)
onClick = {
}
addSpan(TextAppearanceSpan(context, R.style.TextAppearance))
span {
text = "Hi"
}
span("Hi")
+"Hi"
link("http://google.com", "Text")
quote(Color.RED, "Text")
subscript("Text")
superscript("Text")
image(getDrawable(R.drawable.ic_fun))
}Caution: Avoid nested text in spans
The following code will cause RuntimeException: Can't nest "World" in spans. This is because you try to nest span with text "World" in its parent span with text "Hello", it does not make any sense.
val text = span {
text = "Hello"
span("World")
}Styles can be overwrite in nested spans, inner span overwrite the outer span.
val text = span {
textColor = Color.BLUE
textSize = dp(20)
+"Simple text"
+"\n"
span("Overwrite foreground") {
textColor = Color.RED
}
+"\n"
span("Overwrite text size") {
textSize = dp(10)
}
}You can create reusable styles and reuse them in multiple spans.
val headerStyle = style {
textColor = Color.BLACK
textStyle = "bold"
textSize = dp(20)
verticalPadding = dp(3)
}
val content = span {
span("Header 1") {
style = headerStyle
}
span {
text = "\n...\n"
}
span("Header 2") {
style = headerStyle
}
}You can set global style by create a style and pass it to the companion object Span.globalStyle.
For example, if your project using a custom typeface, you can apply styles with custom typeface, then you will no need to specify typeface each time you using spans.
Span.globalStyle = style {
typeface = getFont(R.font.pacifico)
}-
text
-
textColor
-
backgroundColor
-
textSize
-
typeface
-
lineSpacing
-
verticalPadding
-
paddingTop
-
paddingBottom
-
onClick
-
fontFamily: include "monospace", "serif", and "sans-serif"
-
textStyle: include "normal", "bold", "italic", and "bold_italic"
-
alignment: include "normal", "opposite", and "center"
-
textDecorationLine: include "none", "underline", "line-through", and "underline line-through"
-
link: URLSpan
-
quote: QuoteSpan
-
superscript: SuperscriptSpan
-
subscript: SubscriptSpan
-
image: ImageSpan, include "bottom" and "baseline" alignment
-
addSpan: Add custom span
Copyright 2018 Jun Gu
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this 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.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent