android/testSrc/com/android/tools/idea/ui/ProportionalLayoutTest.java

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * 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.android.tools.idea.ui;

import org.junit.Test;

import javax.swing.*;
import java.awt.*;

import static org.fest.assertions.Assertions.assertThat;

public final class ProportionalLayoutTest {
  @Test
  public void columnCountMatchesLayoutDefinition() {
    ProportionalLayout layout = ProportionalLayout.fromString("Fit,*,123px");
    assertThat(layout.getNumColumns()).isEqualTo(3);
  }

  @Test
  public void minimumWidthCalculationUsesFitValues() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("Fit,Fit"));

    Component col0 = Box.createHorizontalStrut(80);
    Component col1 = Box.createHorizontalStrut(20);

    panel.add(col0, new ProportionalLayout.Constraint(0, 0));
    panel.add(col1, new ProportionalLayout.Constraint(0, 1));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(100);
  }

  @Test
  public void minimumWidthCalculationFixedValuesOverrideComponentSizes() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("100px,50px"));

    Component col0 = Box.createHorizontalStrut(90);
    Component col1 = Box.createHorizontalStrut(90);

    panel.add(col0, new ProportionalLayout.Constraint(0, 0));
    panel.add(col1, new ProportionalLayout.Constraint(0, 1));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(150);
  }

  @Test
  public void fitWidthChoosesLargestValueAcrossMultipleRows() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("Fit,Fit"));

    final Component row0col0 = Box.createHorizontalStrut(100);
    final Component row1col0 = Box.createHorizontalStrut(300);
    final Component row3col0 = Box.createHorizontalStrut(200);

    final Component row0col1 = Box.createHorizontalStrut(500);
    final Component row2col1 = Box.createHorizontalStrut(400);
    final Component row4col1 = Box.createHorizontalStrut(100);

    panel.add(row0col0, new ProportionalLayout.Constraint(0, 0));
    panel.add(row1col0, new ProportionalLayout.Constraint(1, 0));
    panel.add(row3col0, new ProportionalLayout.Constraint(3, 0));

    panel.add(row0col1, new ProportionalLayout.Constraint(0, 1));
    panel.add(row2col1, new ProportionalLayout.Constraint(2, 1));
    panel.add(row4col1, new ProportionalLayout.Constraint(4, 1));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(800);

    assertThat(row0col0.getWidth()).isEqualTo(300);
    assertThat(row1col0.getWidth()).isEqualTo(300);
    assertThat(row3col0.getWidth()).isEqualTo(300);

    assertThat(row0col1.getWidth()).isEqualTo(500);
    assertThat(row2col1.getWidth()).isEqualTo(500);
    assertThat(row4col1.getWidth()).isEqualTo(500);
  }

  @Test
  public void proportionalColumnsTakeRemainingSpace() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("100px,Fit,3*,*,50px"));
    panel.setPreferredSize(new Dimension(300, 20));

    // Col 1 = 100, Col 5 = 50
    // Col 2 = Fit to size 50
    // Total width is 300
    // Leftover space is 100 pixels

    final Component col0 = new JPanel();
    final Component col1 = Box.createHorizontalStrut(50);
    final Component col2 = new JPanel();
    final Component col3 = new JPanel();
    final Component col4 = new JPanel();

    panel.add(col0, new ProportionalLayout.Constraint(0, 0));
    panel.add(col1, new ProportionalLayout.Constraint(0, 1));
    panel.add(col2, new ProportionalLayout.Constraint(0, 2));
    panel.add(col3, new ProportionalLayout.Constraint(0, 3));
    panel.add(col4, new ProportionalLayout.Constraint(0, 4));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(300);

    assertThat(col0.getWidth()).isEqualTo(100);
    assertThat(col1.getWidth()).isEqualTo(50);
    assertThat(col2.getWidth()).isEqualTo(75);
    assertThat(col3.getWidth()).isEqualTo(25);
    assertThat(col4.getWidth()).isEqualTo(50);
  }

  @Test
  public void preferredSizeCalculationMakesRoomForProportionalColumns() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("*,2*,3*,4*"));

    // Col 0 - 10%
    // Col 1 - 20%
    // Col 2 - 30%
    // Col 3 - 40%

    final Component col0 = Box.createHorizontalStrut(40); // Needs overall width to be 400
    final Component col1 = Box.createHorizontalStrut(50); // Needs overall width to be 250
    final Component col2 = Box.createHorizontalStrut(30); // Needs overall width to be 100
    final Component col3 = Box.createHorizontalStrut(80); // Needs overall width to be 200

    panel.add(col0, new ProportionalLayout.Constraint(0, 0));
    panel.add(col1, new ProportionalLayout.Constraint(0, 1));
    panel.add(col2, new ProportionalLayout.Constraint(0, 2));
    panel.add(col3, new ProportionalLayout.Constraint(0, 3));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(400);
    assertThat(col0.getWidth()).isEqualTo(40);
    assertThat(col1.getWidth()).isEqualTo(80);
    assertThat(col2.getWidth()).isEqualTo(120);
    assertThat(col3.getWidth()).isEqualTo(160);
  }

  @Test
  public void minimumSizeCalculationCollapsesProportionalColumns() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("10px,990*,*,20px,3*"));

    mockPackPanel(panel);

    assertThat(panel.getMinimumSize().getWidth()).isEqualTo(30);
  }

  @Test
  public void heightCalculationSkipsEmptyRows() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("100px"));

    final Component row0 = Box.createVerticalStrut(20);
    final Component row2 = Box.createVerticalStrut(50);

    panel.add(row0, new ProportionalLayout.Constraint(0, 0));
    panel.add(row2, new ProportionalLayout.Constraint(2, 0));

    mockPackPanel(panel);

    assertThat(panel.getHeight()).isEqualTo(70);

    assertThat(row0.getHeight()).isEqualTo(20);
    assertThat(row2.getY()).isEqualTo(20);
    assertThat(row2.getHeight()).isEqualTo(50);
  }

  @Test
  public void layoutTakesInsetsIntoAccount() throws Exception {
    final JPanel panel = new JPanel(ProportionalLayout.fromString("*"));
    panel.setPreferredSize(new Dimension(300, 30));

    final Component cell = new JPanel();
    panel.add(cell, new ProportionalLayout.Constraint(0, 0));

    final int top = 1;
    final int left = 2;
    final int bottom = 3;
    final int right = 4;
    panel.setBorder(BorderFactory.createEmptyBorder(top, left, bottom, right));

    mockPackPanel(panel);

    assertThat(panel.getWidth()).isEqualTo(300);
    assertThat(panel.getHeight()).isEqualTo(30);
    assertThat(cell.getWidth()).isEqualTo(300 - left - right);
  }

  /**
   * This fake pack method aims to imitate Frame.pack(), which we can't call in headless mode.
   */
  private static void mockPackPanel(JPanel panel) {
    panel.setSize(panel.getPreferredSize());
    panel.doLayout();
  }
}