Simplify a call, and add comments (A2)

Since the function has to be modified heavily but does a lot
of non-trivial work, add a wealth of comments explaining what
it does and why so as to facilitate understanding the changes
to come.

Bug: 4967874
Change-Id: I6c21aea15f161d807035f279dfb7d1b98b3e9144
main
Jean Chalard 2012-09-13 14:56:56 +09:00
parent 9d1c73ffd8
commit 3d54e1c1ec
2 changed files with 67 additions and 18 deletions

View File

@ -204,8 +204,7 @@ public class RichInputConnection {
} }
// This never calls InputConnection#getCapsMode - in fact, it's a static method that // This never calls InputConnection#getCapsMode - in fact, it's a static method that
// never blocks or initiates IPC. // never blocks or initiates IPC.
return StringUtils.getCapsMode(mCommittedTextBeforeComposingText, return StringUtils.getCapsMode(mCommittedTextBeforeComposingText, inputType);
mCommittedTextBeforeComposingText.length(), inputType);
} }
public CharSequence getTextBeforeCursor(final int i, final int j) { public CharSequence getTextBeforeCursor(final int i, final int j) {

View File

@ -208,7 +208,6 @@ public final class StringUtils {
* issues). This will change in the future as we simplify the code for our use and fix bugs. * issues). This will change in the future as we simplify the code for our use and fix bugs.
* *
* @param cs The text that should be checked for caps modes. * @param cs The text that should be checked for caps modes.
* @param off Location in the text at which to check.
* @param reqModes The modes to be checked: may be any combination of * @param reqModes The modes to be checked: may be any combination of
* {@link #CAP_MODE_CHARACTERS}, {@link #CAP_MODE_WORDS}, and * {@link #CAP_MODE_CHARACTERS}, {@link #CAP_MODE_WORDS}, and
* {@link #CAP_MODE_SENTENCES}. * {@link #CAP_MODE_SENTENCES}.
@ -218,52 +217,93 @@ public final class StringUtils {
* {@link #CAP_MODE_CHARACTERS}, {@link #CAP_MODE_WORDS}, and * {@link #CAP_MODE_CHARACTERS}, {@link #CAP_MODE_WORDS}, and
* {@link #CAP_MODE_SENTENCES}. * {@link #CAP_MODE_SENTENCES}.
*/ */
public static int getCapsMode(CharSequence cs, int off, int reqModes) { public static int getCapsMode(CharSequence cs, int reqModes) {
if (off < 0) {
return 0;
}
int i; int i;
char c; char c;
int mode = 0; int mode = 0;
// Quick description of what we want to do:
// CAP_MODE_CHARACTERS is always on.
// CAP_MODE_WORDS is on if there is some whitespace before the cursor.
// CAP_MODE_SENTENCES is on if there is some whitespace before the cursor, and the end
// of a sentence just before that.
// We ignore opening parentheses and the like just before the cursor for purposes of
// finding whitespace for WORDS and SENTENCES modes.
// The end of a sentence ends with a period, question mark or exclamation mark. If it's
// a period, it also needs not to be an abbreviation, which means it also needs to either
// be immediately preceded by punctuation, or by a string of only letters with single
// periods interleaved.
// Step 1 : check for cap mode characters. If it's looked for, it's always on.
if ((reqModes & TextUtils.CAP_MODE_CHARACTERS) != 0) { if ((reqModes & TextUtils.CAP_MODE_CHARACTERS) != 0) {
mode |= TextUtils.CAP_MODE_CHARACTERS; mode |= TextUtils.CAP_MODE_CHARACTERS;
} }
if ((reqModes & (TextUtils.CAP_MODE_WORDS | TextUtils.CAP_MODE_SENTENCES)) == 0) { if ((reqModes & (TextUtils.CAP_MODE_WORDS | TextUtils.CAP_MODE_SENTENCES)) == 0) {
// Here we are not looking for words or sentences modes, so since we already evaluated
// mode characters, we can return.
return mode; return mode;
} }
// Back over allowed opening punctuation. // Step 2 : Skip (ignore at the end of input) any opening punctuation. This includes
for (i = off; i > 0; i--) { // opening parentheses, brackets, opening quotes, everything that *opens* a span of
// text in the linguistic sense. In RTL languages, this is still an opening sign, although
// it may look like a right parenthesis for example. We also include double quote and
// single quote since they aren't start punctuation in the unicode sense, but should still
// be skipped for English. TODO: does this depend on the language?
for (i = cs.length(); i > 0; i--) {
c = cs.charAt(i - 1); c = cs.charAt(i - 1);
if (c != '"' && c != '\'' && Character.getType(c) != Character.START_PUNCTUATION) { if (c != '"' && c != '\'' && Character.getType(c) != Character.START_PUNCTUATION) {
break; break;
} }
} }
// Start of paragraph, with optional whitespace. // We are now on the character that precedes any starting punctuation, so in the most
// frequent case this will be whitespace or a letter, although it may occasionally be a
// start of line, or some symbol.
// Step 3 : Search for the start of a paragraph. From the starting point computed in step 2,
// we go back over any space or tab char sitting there. We find the start of a paragraph
// if the first char that's not a space or tab is a start of line (as in, either \n or
// start of text).
int j = i; int j = i;
while (j > 0 && ((c = cs.charAt(j - 1)) == ' ' || c == '\t')) { while (j > 0 && ((c = cs.charAt(j - 1)) == ' ' || c == '\t')) {
j--; j--;
} }
if (j == 0 || cs.charAt(j - 1) == '\n') { if (j == 0 || cs.charAt(j - 1) == '\n') {
// Here we know we are at the start of a paragraph, so we turn on word mode.
// Note: I think this is entirely buggy. It will return mode words even if the app
// didn't request it, and it will fail to return sentence mode even if this is actually
// the start of a sentence. As it happens, Latin IME client code considers that mode
// word *implies* mode sentence and tests for non-zeroness, so it happens to work.
return mode | TextUtils.CAP_MODE_WORDS; return mode | TextUtils.CAP_MODE_WORDS;
} }
// Or start of word if we are that style.
if ((reqModes & TextUtils.CAP_MODE_SENTENCES) == 0) { if ((reqModes & TextUtils.CAP_MODE_SENTENCES) == 0) {
// If we don't have to check for mode sentence, then we know all we need to know
// already. Either we have whitespace immediately before index i and we are at the
// start of a word, or we don't and we aren't. But we just went over any whitespace
// just before i and in fact j points before any whitespace, so if i != j that means
// there is such whitespace. In this case, we have mode words.
if (i != j) mode |= TextUtils.CAP_MODE_WORDS; if (i != j) mode |= TextUtils.CAP_MODE_WORDS;
return mode; return mode;
} }
// There must be a space if not the start of paragraph.
if (i == j) { if (i == j) {
// Finally, if we don't have whitespace before index i, it means neither mode words
// nor mode sentences should be on so we can return right away.
return mode; return mode;
} }
// Please note that because of the reqModes & CAP_MODE_SENTENCES test a few lines above,
// we know that mode sentences is being requested.
// Back over allowed closing punctuation. // Step 4 : Search for sentence mode.
for (; j > 0; j--) { for (; j > 0; j--) {
// Here we look to go over any closing punctuation. This is because in dominant variants
// of English, the final period is placed within double quotes and maybe other closing
// punctuation signs.
// TODO: this is wrong for almost everything except American typography rules for
// English. It's wrong for British typography rules for English, it's wrong for French,
// it's wrong for German, it's wrong for Spanish, and possibly everything else.
// (note that American rules and British rules have nothing to do with en_US and en_GB,
// as both rules are used in both countries - it's merely a name for the set of rules)
c = cs.charAt(j - 1); c = cs.charAt(j - 1);
if (c != '"' && c != '\'' && Character.getType(c) != Character.END_PUNCTUATION) { if (c != '"' && c != '\'' && Character.getType(c) != Character.END_PUNCTUATION) {
break; break;
@ -273,8 +313,18 @@ public final class StringUtils {
if (j > 0) { if (j > 0) {
c = cs.charAt(j - 1); c = cs.charAt(j - 1);
if (c == '.' || c == '?' || c == '!') { if (c == '.' || c == '?' || c == '!') {
// Do not capitalize if the word ends with a period but // Here we found a marker for sentence end (we consider these to be one of
// also contains a period, in which case it is an abbreviation. // either . or ? or ! only). So this is probably the end of a sentence, but if we
// found a period, we still want to check the case where this is a abbreviation
// period rather than a full stop. To do this, we look for a period within a word
// before the period we just found; if any, we take that to mean it was an
// abbreviation.
// A typical example of the above is "In the U.S. ", where the last period is
// not a full stop and we should not capitalize.
// TODO: the rule below is broken. In particular it fails for runs of periods,
// whatever the reason. In the example "in the U.S..", the last period is a full
// stop following the abbreviation period, and we should capitalize but we don't.
// Likewise, "I don't know... " should capitalize, but fails to do so.
if (c == '.') { if (c == '.') {
for (int k = j - 2; k >= 0; k--) { for (int k = j - 2; k >= 0; k--) {
c = cs.charAt(k); c = cs.charAt(k);