1 files changed, 197 insertions, 0 deletions
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/history/BaseDiffFromHistoryHandler.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/history/BaseDiffFromHistoryHandler.java
new file mode 100644
index 000000000000..8a16ba6a481f
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+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/history/BaseDiffFromHistoryHandler.java
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2000-2014 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.vcs.history;
+
+import com.intellij.openapi.actionSystem.AnActionEvent;
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.progress.ProgressIndicator;
+import com.intellij.openapi.progress.Task;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.ui.DialogBuilder;
+import com.intellij.openapi.ui.MessageType;
+import com.intellij.openapi.util.Couple;
+import com.intellij.openapi.vcs.FilePath;
+import com.intellij.openapi.vcs.VcsException;
+import com.intellij.openapi.vcs.changes.Change;
+import com.intellij.openapi.vcs.changes.ui.ChangesBrowser;
+import com.intellij.openapi.vcs.ui.VcsBalloonProblemNotifier;
+import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+/**
+ * @author Konstantin Kolosovsky.
+ */
+public abstract class BaseDiffFromHistoryHandler<T extends VcsFileRevision> implements DiffFromHistoryHandler {
+
+  private static final Logger LOG = Logger.getInstance(BaseDiffFromHistoryHandler.class);
+
+  @NotNull protected final Project myProject;
+
+  protected BaseDiffFromHistoryHandler(@NotNull Project project) {
+    myProject = project;
+  }
+
+  @Override
+  public void showDiffForOne(@NotNull AnActionEvent e,
+                             @NotNull FilePath filePath,
+                             @NotNull VcsFileRevision previousRevision,
+                             @NotNull VcsFileRevision revision) {
+    doShowDiff(filePath, previousRevision, revision, false);
+  }
+
+  @Override
+  public void showDiffForTwo(@NotNull FilePath filePath, @NotNull VcsFileRevision revision1, @NotNull VcsFileRevision revision2) {
+    doShowDiff(filePath, revision1, revision2, true);
+  }
+
+  @SuppressWarnings("unchecked")
+  protected void doShowDiff(@NotNull FilePath filePath,
+                            @NotNull VcsFileRevision revision1,
+                            @NotNull VcsFileRevision revision2,
+                            boolean autoSort) {
+    if (!filePath.isDirectory()) {
+      VcsHistoryUtil.showDifferencesInBackground(myProject, filePath, revision1, revision2, autoSort);
+    }
+    else if (revision1.equals(VcsFileRevision.NULL)) {
+      T right = (T)revision2;
+      showAffectedChanges(filePath, right);
+    }
+    else if (revision2 instanceof CurrentRevision) {
+      T left = (T)revision1;
+      showChangesBetweenRevisions(filePath, left, null);
+    }
+    else {
+      T left = (T)revision1;
+      T right = (T)revision2;
+      if (autoSort) {
+        Couple<VcsFileRevision> pair = VcsHistoryUtil.sortRevisions(revision1, revision2);
+        left = (T)pair.first;
+        right = (T)pair.second;
+      }
+      showChangesBetweenRevisions(filePath, left, right);
+    }
+  }
+
+  protected void showChangesBetweenRevisions(@NotNull final FilePath path, @NotNull final T rev1, @Nullable final T rev2) {
+    new CollectChangesTask("Comparing revisions...") {
+
+      @NotNull
+      @Override
+      public List<Change> getChanges() throws VcsException {
+        return getChangesBetweenRevisions(path, rev1, rev2);
+      }
+
+      @NotNull
+      @Override
+      public String getDialogTitle() {
+        return getChangesBetweenRevisionsDialogTitle(path, rev1, rev2);
+      }
+    }.queue();
+  }
+
+  protected void showAffectedChanges(@NotNull final FilePath path, @NotNull final T rev) {
+    new CollectChangesTask("Collecting affected changes...") {
+
+      @NotNull
+      @Override
+      public List<Change> getChanges() throws VcsException {
+        return getAffectedChanges(path, rev);
+      }
+
+      @NotNull
+      @Override
+      public String getDialogTitle() {
+        return getAffectedChangesDialogTitle(path, rev);
+      }
+    }.queue();
+  }
+
+  // rev2 == null -> compare rev1 with local
+  // rev2 != null -> compare rev1 with rev2
+  @NotNull
+  protected abstract List<Change> getChangesBetweenRevisions(@NotNull final FilePath path, @NotNull final T rev1, @Nullable final T rev2)
+    throws VcsException;
+
+  @NotNull
+  protected abstract List<Change> getAffectedChanges(@NotNull final FilePath path, @NotNull final T rev) throws VcsException;
+
+  @NotNull
+  protected abstract String getPresentableName(@NotNull T revision);
+
+  protected void showChangesDialog(@NotNull String title, @NotNull List<Change> changes) {
+    DialogBuilder dialogBuilder = new DialogBuilder(myProject);
+
+    dialogBuilder.setTitle(title);
+    dialogBuilder.setActionDescriptors(new DialogBuilder.ActionDescriptor[]{new DialogBuilder.CloseDialogAction()});
+    final ChangesBrowser changesBrowser =
+      new ChangesBrowser(myProject, null, changes, null, false, true, null, ChangesBrowser.MyUseCase.COMMITTED_CHANGES, null);
+    changesBrowser.setChangesToDisplay(changes);
+    dialogBuilder.setCenterPanel(changesBrowser);
+    dialogBuilder.showNotModal();
+  }
+
+  protected void showError(@NotNull VcsException e, @NotNull String logMessage) {
+    LOG.info(logMessage, e);
+    VcsBalloonProblemNotifier.showOverVersionControlView(myProject, e.getMessage(), MessageType.ERROR);
+  }
+
+  @NotNull
+  protected String getChangesBetweenRevisionsDialogTitle(@NotNull final FilePath path, @NotNull final T rev1, @Nullable final T rev2) {
+    String rev1Title = getPresentableName(rev1);
+
+    return rev2 != null
+           ? String.format("Difference between %s and %s in %s", rev1Title, getPresentableName(rev2), path.getName())
+           : String.format("Difference between %s and local version in %s", rev1Title, path.getName());
+  }
+
+  @NotNull
+  protected String getAffectedChangesDialogTitle(@NotNull final FilePath path, @NotNull final T rev) {
+    return String.format("Initial commit %s in %s", getPresentableName(rev), path.getName());
+  }
+
+  protected abstract class CollectChangesTask extends Task.Backgroundable {
+
+    private List<Change> myChanges;
+
+    public CollectChangesTask(@NotNull String title) {
+      super(BaseDiffFromHistoryHandler.this.myProject, title);
+    }
+
+    @Override
+    public void run(@NotNull ProgressIndicator indicator) {
+      try {
+        myChanges = getChanges();
+      }
+      catch (VcsException e) {
+        showError(e, "Error during task: " + getDialogTitle());
+      }
+    }
+
+    @NotNull
+    public abstract List<Change> getChanges() throws VcsException;
+
+    @NotNull
+    public abstract String getDialogTitle();
+
+    @Override
+    public void onSuccess() {
+      showChangesDialog(getDialogTitle(), ContainerUtil.notNullize(myChanges));
+    }
+  }
+}