ApproximationFragment.java

/*
 * Copyright 2000-2015 JetBrains s.r.o.
 *
 * 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.
 */
package com.intellij.openapi.editor.impl.view;

import org.jetbrains.annotations.NotNull;

import java.awt.*;

/**
 * Used for quick estimation of editor's viewable area size (without full text layout)
 */
class ApproximationFragment implements LineFragment {
  private final int myLength;
  private final int myColumnCount;
  private final float myWidth;

  ApproximationFragment(int length, int columnCount, float charWidth) {
    myLength = length;
    myColumnCount = columnCount;
    myWidth = charWidth * columnCount;
  }

  @Override
  public int getLength() {
    return myLength;
  }

  @Override
  public int getLogicalColumnCount(int startColumn) {
    return myColumnCount;
  }

  @Override
  public int getVisualColumnCount(float startX) {
    return myColumnCount;
  }

  @Override
  public int logicalToVisualColumn(float startX, int startColumn, int column) {
    return column;
  }

  @Override
  public int visualToLogicalColumn(float startX, int startColumn, int column) {
    return column;
  }

  @Override
  public float visualColumnToX(float startX, int column) {
    return column < myColumnCount ? 0 : myWidth;
  }

  @Override
  public int[] xToVisualColumn(float startX, float x) {
    float relX = x - startX;
    int column = relX < myWidth / 2 ? 0 : myColumnCount;
    return new int[] {column, relX <= visualColumnToX(startX, column) ? 0 : 1};
  }

  @Override
  public float offsetToX(float startX, int startOffset, int offset) {
    return startX + (offset < myLength ? 0 : myWidth);
  }

  @Override
  public void draw(Graphics2D g, float x, float y, int startColumn, int endColumn) {
    throw new UnsupportedOperationException();
  }

  @NotNull
  @Override
  public LineFragment subFragment(int startOffset, int endOffset) {
    throw new UnsupportedOperationException();
  }
}