platform/platform-impl/src/com/intellij/openapi/wm/impl/CommandProcessor.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.intellij.openapi.wm.impl;
  17
  18 import com.intellij.openapi.application.ApplicationManager;
  19 import com.intellij.openapi.application.ModalityState;
  20 import com.intellij.openapi.diagnostic.Logger;
  21 import com.intellij.openapi.util.Condition;
  22 import com.intellij.openapi.wm.impl.commands.FinalizableCommand;
  23 import org.jetbrains.annotations.NotNull;
  24 import org.jetbrains.annotations.Nullable;
  25
  26 import java.util.ArrayList;
  27 import java.util.List;
  28
  29 public final class CommandProcessor implements Runnable {
  30   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.wm.impl.CommandProcessor");
  31   private final Object myLock = new Object();
  32
  33   private final List<CommandGroup> myCommandGroupList = new ArrayList<CommandGroup>();
  34   private int myCommandCount;
  35
  36   public final int getCommandCount() {
  37     synchronized (myLock) {
  38       return myCommandCount;
  39     }
  40   }
  41
  42   /**
  43    * Executes passed batch of commands. Note, that the processor surround the
  44    * commands with BlockFocusEventsCmd - UnbockFocusEventsCmd. It's required to
  45    * prevent focus handling of events which is caused by the commands to be executed.
  46    */
  47   public final void execute(@NotNull List<FinalizableCommand> commandList, @NotNull Condition expired) {
  48     synchronized (myLock) {
  49       final boolean isBusy = myCommandCount > 0;
  50
  51       final CommandGroup commandGroup = new CommandGroup(commandList, expired);
  52       myCommandGroupList.add(commandGroup);
  53       myCommandCount += commandList.size();
  54
  55       if (!isBusy) {
  56         run();
  57       }
  58     }
  59   }
  60
  61   public final void run() {
  62     synchronized (myLock) {
  63       final CommandGroup commandGroup = getNextCommandGroup();
  64       if (commandGroup == null || commandGroup.isEmpty()) return;
  65
  66       final Condition conditionForGroup = commandGroup.getExpireCondition();
  67
  68       final FinalizableCommand command = commandGroup.takeNextCommand();
  69       myCommandCount--;
  70
  71       final Condition expire = command.getExpireCondition() != null ? command.getExpireCondition() : conditionForGroup;
  72
  73       if (LOG.isDebugEnabled()) {
  74         LOG.debug("CommandProcessor.run " + command);
  75       }
  76       // max. I'm not actually quite sure this should have NON_MODAL modality but it should
  77       // definitely have some since runnables in command list may (and do) request some PSI activity
  78       final boolean queueNext = myCommandCount > 0;
  79       ApplicationManager.getApplication().getInvokator().invokeLater(command, ModalityState.NON_MODAL, expire == null ? Condition.FALSE : expire).doWhenDone(new Runnable() {
  80         public void run() {
  81           if (queueNext) {
  82             CommandProcessor.this.run();
  83           }
  84         }
  85       });
  86     }
  87   }
  88
  89   @Nullable
  90   private CommandGroup getNextCommandGroup() {
  91     while (!myCommandGroupList.isEmpty()) {
  92       final CommandGroup candidate = myCommandGroupList.get(0);
  93       if (!candidate.isEmpty()) {
  94         return candidate;
  95       }
  96       myCommandGroupList.remove(candidate);
  97     }
  98
  99     return null;
 100   }
 101
 102   private static class CommandGroup {
 103     private final List<FinalizableCommand> myList;
 104     private Condition myExpireCondition;
 105
 106     private CommandGroup(@NotNull List<FinalizableCommand> list, @NotNull Condition expireCondition) {
 107       myList = list;
 108       myExpireCondition = expireCondition;
 109     }
 110
 111     public Condition getExpireCondition() {
 112       return myExpireCondition;
 113     }
 114
 115     public boolean isEmpty() {
 116       return myList.isEmpty();
 117     }
 118
 119     public FinalizableCommand takeNextCommand() {
 120       FinalizableCommand command = myList.remove(0);
 121       if (isEmpty()) {
 122         // memory leak otherwise
 123         myExpireCondition = Condition.TRUE;
 124       }
 125       return command;
 126     }
 127   }
 128 }