android/src/org/jetbrains/android/formatter/AndroidXmlFormattingModelBuilder.java

package org.jetbrains.android.formatter;

import com.intellij.formatting.*;
import com.intellij.lang.ASTNode;
import com.intellij.lang.xml.XmlFormattingModelBuilder;
import com.intellij.openapi.util.TextRange;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.codeStyle.CodeStyleSettings;
import com.intellij.psi.formatter.xml.XmlBlock;
import com.intellij.psi.formatter.xml.XmlPolicy;
import com.intellij.psi.formatter.xml.XmlTagBlock;
import com.intellij.psi.xml.XmlFile;
import com.intellij.util.xml.DomFileDescription;
import com.intellij.util.xml.DomManager;
import org.jetbrains.android.dom.AndroidResourceDomFileDescription;
import org.jetbrains.android.dom.color.ColorDomFileDescription;
import org.jetbrains.android.dom.drawable.DrawableStateListDomFileDescription;
import org.jetbrains.android.dom.layout.LayoutDomFileDescription;
import org.jetbrains.android.dom.manifest.ManifestDomFileDescription;
import org.jetbrains.android.dom.resources.ResourcesDomFileDescription;
import org.jetbrains.android.facet.AndroidFacet;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * @author Eugene.Kudelevsky
 */
public class AndroidXmlFormattingModelBuilder implements CustomFormattingModelBuilder {
  private final XmlFormattingModelBuilder myXmlFormattingModelBuilder = new XmlFormattingModelBuilder();

  @Override
  public boolean isEngagedToFormat(PsiElement context) {
    return getContextSpecificSettings(context) != null;
  }

  @NotNull
  @Override
  public FormattingModel createModel(PsiElement element, CodeStyleSettings settings) {
    final FormattingModel baseModel = myXmlFormattingModelBuilder.createModel(element, settings);
    final AndroidXmlCodeStyleSettings baseSettings = AndroidXmlCodeStyleSettings.getInstance(settings);

    if (!baseSettings.USE_CUSTOM_SETTINGS) {
      return baseModel;
    }
    final ContextSpecificSettingsProviders.Provider provider = getContextSpecificSettings(element);
    final AndroidXmlCodeStyleSettings.MySettings s = provider != null ? provider.getSettings(baseSettings) : null;
    return s != null ? new DelegatingFormattingModel(baseModel, createDelegatingBlock(baseModel, s, settings)) : baseModel;
  }

  private static Block createDelegatingBlock(FormattingModel model,
                                     AndroidXmlCodeStyleSettings.MySettings customSettings,
                                     CodeStyleSettings settings) {
    final Block block = model.getRootBlock();

    if (block instanceof XmlBlock) {
      final XmlBlock b = (XmlBlock)block;
      final XmlPolicy policy = customSettings.createXmlPolicy(settings, model.getDocumentModel());
      return new XmlBlock(b.getNode(), b.getWrap(), b.getAlignment(), policy, b.getIndent(), b.getTextRange()) {
        @Override
        protected XmlTagBlock createTagBlock(ASTNode child, Indent indent, Wrap wrap, Alignment alignment) {
          return new XmlTagBlock(child, wrap, alignment, myXmlFormattingPolicy,
                                 indent != null ? indent : Indent.getNoneIndent(),
                                 isPreserveSpace());
        }
      };
    }
    else {
      return block;
    }
  }

  @Nullable
  @Override
  public TextRange getRangeAffectingIndent(PsiFile file, int offset, ASTNode elementAtOffset) {
    return myXmlFormattingModelBuilder.getRangeAffectingIndent(file, offset, elementAtOffset);
  }

  @Nullable
  private static ContextSpecificSettingsProviders.Provider getContextSpecificSettings(PsiElement context) {
    final PsiFile file = context.getContainingFile();

    if (!(file instanceof XmlFile) ||
        AndroidFacet.getInstance(file) == null) {
      return null;
    }
    final DomFileDescription<?> description = DomManager.getDomManager(
      context.getProject()).getDomFileDescription((XmlFile)file);
    if (description instanceof LayoutDomFileDescription) {
      return ContextSpecificSettingsProviders.LAYOUT;
    }
    else if (description instanceof ManifestDomFileDescription) {
      return ContextSpecificSettingsProviders.MANIFEST;
    }
    else if (description instanceof ResourcesDomFileDescription ||
             description instanceof DrawableStateListDomFileDescription ||
             description instanceof ColorDomFileDescription) {
      return ContextSpecificSettingsProviders.VALUE_RESOURCE_FILE;
    }
    else if (description instanceof AndroidResourceDomFileDescription) {
      return ContextSpecificSettingsProviders.OTHER;
    }
    return null;
  }
}