javax0.jamal.snippet.TrimLines Maven / Gradle / Ivy
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package javax0.jamal.snippet;
import javax0.jamal.api.BadSyntax;
import javax0.jamal.api.InnerScopeDependent;
import javax0.jamal.api.Input;
import javax0.jamal.api.Macro;
import javax0.jamal.api.Position;
import javax0.jamal.api.Processor;
import javax0.jamal.tools.Params;
import javax0.jamal.tools.Scanner;
/**
* Take the argument of the macro and removes N spaces from the start of each line so that there is at least one line
* that does not start with a space character.
*
* This can be used, when a snippet is included into the macro file and some program code is tabulated. In that case
* this snippet will be moved to the left as much as possible.
*/
@Macro.Name({"trimLines", "trim"})
public class TrimLines implements Macro, InnerScopeDependent, BlockConverter, Scanner.FirstLine {
// end snippet
// snippet trimLinesStart
@Override
public String evaluate(Input in, Processor processor) throws BadSyntax {
final var scanner = newScanner(in, processor);
final var margin = scanner.number("margin").defaultValue(0);
final var trimVertical =scanner.bool("trimVertical");
final var verticalTrimOnly = scanner.bool("verticalTrimOnly", "vtrimOnly");
scanner.done();
//end snippet
final var sb = in.getSB();
convertTextBlock(processor, sb, in.getPosition(), margin.getParam(), trimVertical.getParam(), verticalTrimOnly.getParam());
return sb.toString();
}
@Override
public void convertTextBlock(Processor processor, final StringBuilder sb, final Position pos, final Params.Param... params) throws BadSyntax {
assertParams(3, params);
final var margin = params[0];
final var trimVertical = params[1].asBoolean();
final var verticalTrimOnly = params[2].asBoolean();
final int spacesOnLeft = getMargin(margin);
if (!verticalTrimOnly.is()) {
trimHorizontal(sb, spacesOnLeft);
}
if (trimVertical.is() || verticalTrimOnly.is()) {
trimVertical(sb);
}
}
/**
* Get the margin value. Margin value is usually a simple integer. In some cases, however, it can be specified using
* the alias `trim`. When there is no number specified then the trimming is done to zero space on the left.
*
* This method simply looks at how margin was defined. If it was defined using the alias {@code trim} and the value
* is "true", which usually means that the key-word {@code trim} was standing without any value then the value is
* zero. In all other cases the string value of the parameter is parsed as an int.
*
* Note that you can also write {@code trim=true}, which will also mean zero margin.
*
* @param margin the parameter holder specifying the value of the margin
* @return the int value of the margin.
* @throws BadSyntax if there is a value specified and it is not an integer
*/
private int getMargin(final Params.Param margin) throws BadSyntax {
return "trim".equals(margin.name()) &&
"true".equals(margin.asString().get()) ?
0 :
margin.asInt().get();
}
private static void trimVertical(StringBuilder sb) {
int i = 0;
while (i < sb.length() && sb.charAt(i) == '\n') {
i++;
}
sb.delete(0, i);
while (sb.length() > 1 && sb.charAt(sb.length() - 1) == '\n' && sb.charAt(sb.length() - 2) == '\n') {
sb.delete(sb.length() - 1, sb.length());
}
if (sb.length() > 0 && sb.charAt(sb.length() - 1) == '\n') {
sb.delete(sb.length() - 1, sb.length());
}
}
private static void trimHorizontal(StringBuilder sb, int requestedMargin) {
final int margin = calculateMargin(sb, requestedMargin);
doTrimming(sb, margin);
}
private static void doTrimming(StringBuilder sb, int margin) {
for (int i = 0; i < sb.length(); ) {
if (margin < 0) {
sb.insert(i, " ".repeat(-margin));
} else {
int nlIndex = sb.indexOf("\n", i);
if ((nlIndex >= i + margin) || nlIndex == -1) {
sb.delete(i, i + margin);
}
}
int index = sb.indexOf("\n", i);
if (index == -1) break;
int j = index - 1;
while (i <= j && Character.isWhitespace(sb.charAt(j))) {
j--;
}
sb.delete(j + 1, index);
i = j + 2;
}
}
private static int calculateMargin(StringBuilder sb, int margin) {
int minSpaces = Integer.MAX_VALUE;
for (int i = 0; i < sb.length(); ) {
int spaceCount = 0;
while (i < sb.length() && Character.isWhitespace(sb.charAt(i)) && sb.charAt(i) != '\n') {
i++;
spaceCount++;
}
if (i < sb.length() && sb.charAt(i) != '\n') {
minSpaces = Math.min(minSpaces, spaceCount);
}
int index = sb.indexOf("\n", i);
if (index == -1) break;
i = index + 1;
}
if (minSpaces == Integer.MAX_VALUE) {
minSpaces = 0;
}
minSpaces -= margin;
return minSpaces;
}
}